Square Mile to Square Foot Converter
Convert square miles to square feet with our free online area converter.
Quick Answer
1 Square Mile = 27878400 square feet
Formula: Square Mile × conversion factor = Square Foot
Use the calculator below for instant, accurate conversions.
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Square Mile to Square Foot Calculator
How to Use the Square Mile to Square Foot Calculator:
- Enter the value you want to convert in the 'From' field (Square Mile).
- The converted value in Square Foot will appear automatically in the 'To' field.
- Use the dropdown menus to select different units within the Area category.
- Click the swap button (⇌) to reverse the conversion direction.
How to Convert Square Mile to Square Foot: Step-by-Step Guide
Converting Square Mile to Square Foot involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Square Mile = 27878400 square feetExample Calculation:
Convert 10 square miles: 10 × 27878400 = 278784000 square feet
Disclaimer: For Reference Only
These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.
Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.
Need to convert to other area units?
View all Area conversions →What is a Square Mile and a Square Foot?
and Standards
Mathematical Definition
The square mile (symbol: mi², alternative: sq mi) is a unit of area in the Imperial and US Customary systems, defined as:
The area of a square whose sides each measure exactly one statute mile in length.
Formula: $$ 1 \text{ mi}^2 = 1 \text{ mile} \times 1 \text{ mile} $$
Fundamental Relationships
Within the Imperial/US System:
- 1 mile = 5,280 feet (ft) = 1,760 yards (yd)
- 1 mi² = (5,280 ft)² = 27,878,400 ft²
- 1 mi² = (1,760 yd)² = 3,097,600 yd²
- 1 mi² = 640 acres (fundamental definition)
The 640-Acre Relationship: This is not arbitrary. The US survey system was designed so that:
- 1 section = 1 square mile = 640 acres
- ½ section = 320 acres
- ¼ section = 160 acres (historically a "homestead" size)
- ⅛ section = 80 acres
- 1/16 section = 40 acres
Metric Conversions (Exact):
Based on the 1959 International Yard and Pound Agreement:
- 1 mile = 1.609344 kilometers (exactly)
- 1 mi² = (1.609344 km)² = 2.58998811033 6 km²
Practical Metric Conversions:
- 1 mi² ≈ 2.59 km² (rounded)
- 1 mi² = 258.999 hectares ≈ 259 ha
- 1 mi² = 2,589,988 square meters
Visual Representation
A perfect square mile:
- Each side: 5,280 feet = 1.609 km
- Perimeter: 4 miles = 21,120 feet = 6.44 km
- Diagonal: 1.414 miles = 7,470 feet = 2.28 km
How big is it?
- About 505 soccer fields (FIFA regulation)
- About 484 American football fields (including end zones)
- About 1,280 city blocks (assuming 200 ft × 200 ft blocks)
- A 10-minute walk from one side to the opposite side
and Standards
The square foot is defined as the area of a square with sides measuring exactly one international foot:
1 ft² = (1 foot)² = (12 inches)² = (0.3048 meters)²
Precise Equivalents
- 1 ft² = 144 in² (exactly)
- 1 ft² = 1/9 yd² = 0.1111... yd² (exactly)
- 1 ft² = 0.09290304 m² (exactly, by 1959 definition)
- 1 ft² = 929.0304 cm² (exactly)
- 1 ft² = 92,903.04 mm² (exactly)
- 1 acre = 43,560 ft² (exactly)
- 1 square mile = 27,878,400 ft² (exactly)
International Foot Standard (1959)
The International Yard and Pound Agreement of 1959 defined the international foot as precisely 0.3048 meters, resolving slight differences between the US survey foot and the British imperial foot. This definition makes:
1 square foot = (0.3048 m)² = 0.09290304 m² (exactly)
Before 1959, small variations existed. The US survey foot (still used in some land surveys) is defined as exactly 1200/3937 meters, making the US survey square foot = 0.09290341... m² (about 0.0004% larger—negligible for most purposes).
Symbol Variations
The square foot is represented by multiple symbols:
- ft² (most common, scientific)
- sq ft or sq. ft. (common in real estate)
- SF (architectural drawings, construction documents)
- □′ (rare, using the foot prime symbol)
All represent the same unit.
Note: The Square Mile is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Square Foot belongs to the imperial/US customary system.
History of the Square Mile and Square Foot
and Evolution
The Roman Mile (Ancient Origins)
The word "mile" comes from the Latin "mille passus" (thousand paces).
Roman Definition:
- 1 pace (passus) = 2 steps = 5 Roman feet (pes)
- 1,000 paces = 5,000 Roman feet = 1 Roman mile
- 1 Roman mile ≈ 4,850 modern feet (about 1,480 meters)
Roman Land Measurement:
- Romans used the jugerum (about 2/3 acre) for agricultural land
- Centuriation: land divided into square grids for colonial settlements
- This grid system influenced later European land survey methods
Medieval England: Mile Chaos (500-1500 AD)
Multiple "Miles" Existed Simultaneously:
- Old London Mile: 5,000 feet
- Irish Mile: 6,720 feet (2.048 km)
- Scottish Mile: 5,952 feet (1.814 km)
- Various local miles: ranged from 4,800 to 7,000 feet
Why the confusion?
- Different regions had different "feet" lengths
- Local lords defined their own measurement standards
- Trade and legal disputes were common
The Statute Mile (1593)
Queen Elizabeth I's Parliament (1593):
- Standardized the statute mile at exactly 5,280 feet
- Made it the official measurement for England
- Named "statute" because it was defined by statute (law)
Why 5,280 feet?
- 1 mile = 8 furlongs (furlong = 660 feet, used in agriculture)
- 1 furlong = 10 chains (chain = 66 feet, standard surveyor's chain)
- This made conversions between agricultural measures convenient
Square Mile Standardization:
- As the statute mile was defined, the square mile naturally followed
- 1 mi² = 640 acres (this relationship was crucial for land sales)
British Empire and Colonial Land Surveys (1600s-1800s)
Square Mile in Colonial Administration:
- Used throughout British Empire for measuring:
- Colonial territories
- Land grants to settlers
- Administrative districts
- Natural resources (forests, mining claims)
Challenges:
- Early surveys often inaccurate (limited technology)
- Terrain (mountains, rivers) made perfect square miles impossible
- Native land claims conflicted with colonial grid systems
US Public Land Survey System (1785)
The Land Ordinance of 1785:
Perhaps the most important application of the square mile in history.
Problem: The newly independent United States owned vast unsurveyed western territories (Northwest Territory: modern Ohio, Indiana, Illinois, Michigan, Wisconsin, and part of Minnesota).
Solution: Congress passed the Land Ordinance of 1785, creating a systematic survey grid.
The System:
Township: 6 miles × 6 miles = 36 square miles
- Divided into 36 sections
- Each section numbered 1-36 (specific numbering pattern)
Section: 1 mile × 1 mile = 1 square mile = 640 acres
- The fundamental unit of sale
- Could be subdivided: half-section (320 ac), quarter-section (160 ac), etc.
Quarter-Section: ½ mile × ½ mile = 160 acres
- Became the standard homestead size (Homestead Act of 1862)
- Considered sufficient for a family farm
Impact:
- Surveyed over 1.5 billion acres (2.3 million square miles)
- Used in 30 US states (primarily west of the Ohio River)
- Created the rectangular field patterns visible from aircraft today
- Property descriptions still use this system: "SW¼ of Section 12, Township 3N, Range 4W"
States Using PLSS: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Florida, Idaho, Illinois, Indiana, Iowa, Kansas, Louisiana, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Mexico, North Dakota, Ohio, Oklahoma, Oregon, South Dakota, Utah, Washington, Wisconsin, Wyoming
States NOT Using PLSS (Original 13 colonies plus Texas, Hawaii, Kentucky, Tennessee, Vermont, West Virginia): These states used metes and bounds surveying (descriptive: "from the oak tree to the creek to the stone wall...").
International Yard Agreement (1959)
Standardization of the Yard/Foot/Mile:
- US, UK, Canada, Australia, New Zealand, South Africa agreed
- 1 yard = 0.9144 meters (exactly)
- 1 foot = 0.3048 meters (exactly)
- 1 mile = 1.609344 kilometers (exactly)
- 1 square mile = 2.589988110336 km² (exactly)
Why This Mattered:
- International scientific cooperation required consistent units
- Engineering projects crossing borders needed standards
- Eliminated minor differences between US and UK definitions
US Survey Foot Exception:
- US kept the "US survey foot" (1 ft = 1200/3937 m) for existing land records
- Difference: 2 parts per million (0.0002%)
- Matters for large-scale surveys spanning many miles
- Most states switched to international foot by 2023
Modern Era: Metrication and Persistence (1960-Present)
Global Metrication:
- 1965: UK began metrication (Ordnance Survey switched to km²)
- 1970: Canada officially metricated
- 1975: Australia completed metrication
- 1985: New Zealand fully metricated
US Resistance:
- Metric Conversion Act (1975): voluntary metrication—failed
- Square mile remains standard for US geography, census, planning
- All US atlases, maps, and official statistics use square miles
- Real estate still uses acres and square feet
Current Usage:
- United States: Exclusive standard for geographical areas
- United Kingdom: Mixed use (km² official, mi² still common)
- Canada: km² official, mi² understood by older generations
- Myanmar: Uses square mile
- Liberia: Uses square mile
International Organizations:
- UN, WHO, World Bank: use km²
- US Census Bureau: uses mi²
- CIA World Factbook: provides both mi² and km²
and Evolution
Ancient Origins: The Human Foot (3000 BCE - 1200 CE)
The foot as a length measurement dates to ancient civilizations, where it approximated the length of a human foot:
- Egyptian royal cubit: ~0.525 m, subdivided into "feet" of ~0.30 m
- Greek pous: ~0.296 m (varied by city-state)
- Roman pes: ~0.2967 m (29.67 cm)
- Medieval European feet: Varied from 0.25-0.34 m depending on region
These variations meant "square feet" were inconsistent across regions and time periods. A Roman square foot was about 88 cm² versus a medieval German square foot of up to 100 cm².
English Standardization: From Barleycorns to Royal Feet (1300-1824)
Medieval England attempted standardization through royal decrees:
- Edward I (1305): Defined the inch as "three grains of barley, dry and round, laid end to end," making a foot = 36 barleycorns
- Edward II (1324): Further refined the foot based on the royal standard at Westminster
- Weights and Measures Acts (1700s-1824): Gradually standardized the imperial foot across Britain
The Weights and Measures Act of 1824 officially defined the imperial foot and established consistency across the British Empire. This foot became the basis for square footage in British architecture, land surveying, and real estate.
American Adoption: Colonial Legacy (1600s-1959)
American colonists brought English measurement systems to the New World. After independence, the United States retained imperial units rather than adopting the metric system (despite Thomas Jefferson's advocacy for decimalization).
The US customary foot slightly diverged from the British imperial foot over time due to independent maintenance of measurement standards. By the mid-20th century, the difference was approximately 2 parts per million—tiny, but problematic for precision surveying.
The 1959 International Agreement: Ending the Confusion
The International Yard and Pound Agreement of 1959, signed by the United States, United Kingdom, Canada, Australia, New Zealand, and South Africa, established:
1 international yard = 0.9144 meters (exactly)
1 international foot = 0.3048 meters (exactly)
1 international square foot = 0.09290304 m² (exactly)
This unified the foot globally and aligned imperial units with the metric system through exact conversion factors.
Exception: The US survey foot (1200/3937 meters) remains in use for some land surveys to maintain consistency with historical surveys. This creates a US survey square foot slightly different from the international square foot—a distinction only relevant in precision surveying.
Persistence Despite Metrication (1960s-Present)
Throughout the 20th century, most countries adopted the metric system. However, square feet remain dominant in:
United States: Exclusively uses square feet for residential real estate. All home listings, construction documents, building codes, and HVAC calculations use ft². Metrication efforts failed in the 1970s.
United Kingdom: Officially metricated in 1995, requiring metric units in commerce. However, real estate continues to list properties in both square feet and square meters, with square feet often prominently displayed due to consumer preference and historical familiarity.
Canada: Officially metricated (square meters), but square footage remains common in real estate listings and construction, particularly in regions near the US border.
India, Pakistan, Bangladesh: Use square feet as the primary unit for real estate despite official metrication. Property advertisements overwhelmingly use sq ft.
Hong Kong, Singapore, Malaysia: Mixed systems. Hong Kong historically used square feet but increasingly shows square meters. Singapore mandates square meters but square feet remain understood.
The Real Estate Lock-In Effect
Square footage persists in real estate due to:
- Consumer familiarity: Buyers understand "2,000 sq ft" intuitively from years of exposure
- Historical data: Decades of comparable sales in square feet make valuation easier
- Industry resistance: Realtors, appraisers, and builders resist change due to retraining costs
- Building codes: US building codes specify minimum room sizes in square feet
- Property taxation: Tax assessments based on square footage in many jurisdictions
Common Uses and Applications: square miles vs square feet
Explore the typical applications for both Square Mile (imperial/US) and Square Foot (imperial/US) to understand their common contexts.
Common Uses for square miles
Across Industries
1. Government and Census
US Census Bureau:
- Reports all geographic areas in square miles
- Population density: people per mi²
- Urban area definitions based on mi² thresholds
- Metropolitan Statistical Areas (MSAs) measured in mi²
Land Management:
- Bureau of Land Management (BLM): 247 million acres = 386,000 mi²
- US Forest Service: 193 million acres = 302,000 mi²
- National Park Service: 84 million acres = 131,000 mi²
2. Geography and Cartography
Map Making:
- US Geological Survey (USGS) maps use mi²
- Topographic maps scale in miles
- GIS software in US defaults to square miles
Geographic Information Systems (GIS):
- Area calculations reported in mi² for US audiences
- Spatial analysis uses mi² for US jurisdictions
3. Urban Planning and Development
City Planning:
- Zoning maps measured in mi²
- Service area calculations (fire, police, schools) in mi²
- Transit system coverage in mi²
Infrastructure:
- Road networks: lane-miles (length × lanes)
- Service territories: utilities measured in mi²
- Emergency response zones: mi² coverage areas
4. Real Estate (Large Tracts)
Rural Land Sales:
- Ranches: sometimes listed in mi² (though acres more common)
- Large timber tracts: mi²
- Mining claims: sections (1 mi² = 640 acres)
Commercial Development:
- Master-planned communities: hundreds to thousands of acres (multiple mi²)
- Industrial parks: often measured in mi²
5. Environmental Science and Conservation
Habitat Measurement:
- Wildlife refuges measured in mi²
- Conservation easements: large tracts in mi²
- Wetland restoration projects: mi²
Disaster Assessment:
- Wildfire extent: acres or mi²
- Flood zones: mi² inundated
- Hurricane damage: mi² affected
When to Use square feet
1. Real Estate Listings and Sales
Square footage is the primary metric for home valuation in the US, Canada, and UK. Property listings always specify total square footage, often breaking down:
- Total living area (heated/cooled space)
- Bedroom sizes (sq ft per room)
- Basement area (finished vs. unfinished)
- Garage (often listed separately)
Price per square foot is the key metric for comparable sales analysis:
- National US average (2025): $150-200/sq ft for new construction
- Urban markets (San Francisco, NYC): $400-1,000+/sq ft
- Suburban markets: $100-250/sq ft
- Rural markets: $80-150/sq ft
Example: A 2,000 sq ft home listed at $400,000 = $200/sq ft
2. Construction and Architecture
Blueprints, floor plans, and construction documents use square feet for:
- Floor area calculations (required for building permits)
- Material estimates (flooring, drywall, roofing in sq ft)
- Cost estimating (construction cost per sq ft)
- Zoning compliance (maximum floor area ratio, minimum room sizes)
Construction costs (2025 US averages):
- Budget home: $100-150/sq ft
- Standard home: $150-250/sq ft
- Custom home: $250-400/sq ft
- Luxury home: $400-800+/sq ft
3. Flooring and Home Improvement
Flooring materials (carpet, tile, hardwood, laminate) are purchased by the square foot. Homeowners measure room dimensions to calculate total square footage needed, adding 10-15% for waste.
Calculation example:
- Living room: 15' × 18' = 270 sq ft
- Add 10% waste: 270 × 1.10 = 297 sq ft
- Order 300 sq ft of flooring
Paint coverage: One gallon covers ~350-400 sq ft per coat (varies by surface texture). Calculate wall square footage: (Perimeter × Height) - (window/door areas).
4. HVAC System Design
Heating and cooling systems are sized in BTUs or tons, calculated based on square footage of conditioned space. HVAC contractors use Manual J load calculations that account for:
- Square footage (primary factor)
- Insulation levels (R-values)
- Window area and efficiency
- Climate zone
- Air infiltration rates
Rule of thumb: Oversimplified (1 ton/400 sq ft), but professional calculations adjust for specifics.
5. Property Taxation and Assessment
Many jurisdictions calculate property taxes partially based on square footage. Assessors measure "finished living area" to determine assessed value.
Example: A county might assess homes at $150/sq ft, so a 2,500 sq ft home has an assessed value of $375,000, with property tax = assessed value × tax rate (e.g., $375,000 × 1.2% = $4,500/year).
6. Interior Design and Space Planning
Interior designers use square footage to:
- Determine appropriate furniture sizes for rooms
- Calculate occupancy limits (building codes specify sq ft per person)
- Specify area rug sizes
- Plan layouts and circulation space
Furniture scale guidelines:
- Small bedroom (100 sq ft): Twin/full bed, nightstand, small dresser
- Medium bedroom (150 sq ft): Queen bed, two nightstands, dresser, chair
- Large bedroom (250 sq ft): King bed, full furniture set, seating area
Additional Unit Information
About Square Mile (mi²)
How many acres are in one square mile?
Exactly 640 acres in one square mile. This is a fundamental relationship in the Imperial and US Customary systems.
Historical Origin:
- 1 acre = 1 furlong × 1 chain = 660 ft × 66 ft = 43,560 ft²
- 1 mile = 8 furlongs = 5,280 ft
- 1 mi² = (8 furlongs)² = 64 acres × 10 = 640 acres
Common Subdivisions:
- 1 mi² = 640 acres (full section)
- ½ mi² = 320 acres (half section)
- ¼ mi² = 160 acres (quarter section, homestead)
- ⅛ mi² = 80 acres
- 1/16 mi² = 40 acres
How many square kilometers are in one square mile?
One square mile equals approximately 2.59 square kilometers (2.58998811 km² exactly).
Conversion Formula: $$ 1 \text{ mi}^2 = 2.58998811 \text{ km}^2 $$
Quick Mental Math: Multiply mi² by 2.6
Examples:
- 100 mi² = 259 km²
- 1,000 mi² = 2,590 km²
- 10,000 mi² = 25,900 km²
What is a "section" of land in the US?
In the US Public Land Survey System (PLSS), a section is a unit of land area nominally equivalent to one square mile (640 acres).
Township Organization:
- 1 township = 36 sections arranged in a 6×6 grid
- Each section numbered 1-36 (specific pattern)
- Section 16 often reserved for schools (in original PLSS states)
Legal Land Descriptions:
- "SW¼ of Section 12, Township 3 North, Range 4 West" = 160 acres
- This system used in 30 US states
Actual vs Nominal:
- Sections are "nominally" 1 mi² due to survey errors and Earth's curvature
- Actual sections: typically 635-645 acres
- "Government lots" used to correct discrepancies
Is the square mile an SI unit?
No, the square mile is not part of the International System of Units (SI). It belongs to the British Imperial and US Customary systems.
SI/Metric Equivalents:
- Square kilometer (km²): SI standard for large areas
- Hectare (ha): Accepted for use with SI, especially agriculture
Global Usage:
- US: square miles standard
- UK: mixed (km² official, mi² common)
- Rest of world: almost exclusively km²
How do you visualize a square mile?
Walking Measure:
- 1 mile ≈ 20-minute walk at average pace
- Walking around a square mile: 4 miles = 80-minute walk
Grid Measure:
- Imagine 8 city blocks × 8 city blocks (if blocks are 660 ft)
- About 1,280 standard city blocks (if blocks are 200 ft × 200 ft)
Sports Fields:
- About 484 American football fields (with end zones)
- About 505 FIFA regulation soccer fields
- About 740 standard baseball diamonds
Urban Comparison:
- Downtown core of a medium city
- Major university campus
- Large shopping mall with parking lots
How big is Central Park in square miles?
Central Park (NYC): 1.317 mi² (3.41 km²) = 843 acres
Comparisons:
- 1.3× larger than a standard section
- About 6% of Manhattan's area
- Slightly larger than Monaco (0.78 mi²)
Other Famous Parks:
- Golden Gate Park (SF): 1.017 mi² (2.63 km²)
- Griffith Park (LA): 6.9 mi² (17.9 km²)
- Rock Creek Park (DC): 2.8 mi² (7.2 km²)
What is population density per square mile?
Population density is the number of people per unit area, commonly expressed as people per square mile in the US.
Formula: $$ \text{Density} = \frac{\text{Population}}{\text{Area (mi}^2\text{)}} $$
Example:
- San Francisco: 873,965 people ÷ 47 mi² = 18,595 people/mi²
Density Categories:
- Very high: >10,000 people/mi² (Manhattan: 74,000/mi²)
- High: 5,000-10,000 people/mi² (most urban cores)
- Moderate: 1,000-5,000 people/mi² (suburbs)
- Low: 100-1,000 people/mi² (rural-suburban)
- Very low: <100 people/mi² (rural)
How many square miles is Earth's surface?
Total Earth Surface: 196.9 million mi² (510.1 million km²)
Breakdown:
- Land area: 57.5 million mi² (148.9 million km²) — 29.2%
- Water area: 139.4 million mi² (361.1 million km²) — 70.8%
Continents (Land):
- Asia: 17.2 million mi² (44.6 million km²)
- Africa: 11.7 million mi² (30.4 million km²)
- North America: 9.5 million mi² (24.7 million km²)
- South America: 6.9 million mi² (17.8 million km²)
- Antarctica: 5.5 million mi² (14.2 million km²)
- Europe: 3.9 million mi² (10.2 million km²)
- Australia/Oceania: 3.3 million mi² (8.5 million km²)
Can square miles measure ocean areas?
Yes, square miles can measure ocean areas, though square kilometers are more common internationally.
Oceans by Area:
- Pacific Ocean: 63.8 million mi² (165.2 million km²) — largest
- Atlantic Ocean: 41.1 million mi² (106.5 million km²)
- Indian Ocean: 27.2 million mi² (70.6 million km²)
- Southern Ocean: 7.8 million mi² (20.3 million km²)
- Arctic Ocean: 5.4 million mi² (14.1 million km²) — smallest
Comparison:
- Pacific Ocean alone is larger than all land on Earth combined
What is the area of the continental United States?
Continental (Contiguous) United States: 3,119,885 mi² (8,080,464 km²)
This includes the "Lower 48" states (excludes Alaska and Hawaii).
Breakdown:
- Land area: 2,959,064 mi² (7,663,941 km²)
- Water area: 160,821 mi² (416,522 km²)
Total United States (All 50 states):
- Total area: 3,796,742 mi² (9,833,520 km²)
- Alaska adds 665,384 mi² (1,723,337 km²)
- Hawaii adds 10,931 mi² (28,311 km²)
About Square Foot (ft²)
How big is one square foot visually?
One square foot is a square measuring 12 inches (1 foot) on each side.
Common objects:
- Standard 12"×12" floor tile: Exactly 1 square foot
- Large pizza (14" diameter): About 1.07 sq ft (π×7²/144)
- Sheet of paper (8.5"×11"): 0.65 sq ft (93.5 in² ÷ 144)
- Laptop computer (typical 15"): ~0.7-0.9 sq ft
Hand estimation: A handspan (thumb to pinky) stretched out is roughly 9-10 inches, so imagine a square slightly larger than your handspan on each side.
How many square inches are in a square foot?
Exactly 144 square inches (in²) in one square foot.
Calculation: 1 foot = 12 inches, so 1 ft² = 12" × 12" = 144 in²
Examples:
- 1 ft² = 144 in²
- 2 ft² = 288 in²
- 0.5 ft² = 72 in²
- 10 ft² = 1,440 in²
Use case: Small materials (glass panes, small tiles) sold in square inches can be converted to square feet for larger projects.
How many square feet are in a square yard?
Exactly 9 square feet in one square yard.
Calculation: 1 yard = 3 feet, so 1 yd² = 3' × 3' = 9 ft²
Examples:
- 1 yd² = 9 ft²
- 10 yd² = 90 ft²
- 30 yd² = 270 ft²
- 100 yd² = 900 ft²
Carpet pricing: Carpet is often priced per square yard. To find total cost, divide room sq ft by 9 to get sq yd, then multiply by price per sq yd.
Example: 270 sq ft room ÷ 9 = 30 sq yd. At $25/sq yd, cost = $750.
How do I convert square feet to square meters?
Exact formula: m² = ft² × 0.09290304
Quick approximation: m² ≈ ft² ÷ 10.764 (or ft² ÷ 11 for rough estimates)
Examples:
- 100 ft² = 9.29 m²
- 500 ft² = 46.45 m²
- 1,000 ft² = 92.90 m²
- 2,000 ft² = 185.81 m²
- 3,500 ft² = 325.16 m²
Reverse (m² to ft²): ft² = m² × 10.7639
Memory aid: "Divide square feet by roughly 11 to get square meters" (slightly overestimates, but close)
How many square feet are in an acre?
Exactly 43,560 square feet in one acre.
Calculation: 1 acre = 1 furlong × 1 chain = 660' × 66' = 43,560 ft²
Common fractions:
- 1/4 acre = 10,890 ft²
- 1/2 acre = 21,780 ft²
- 3/4 acre = 32,670 ft²
- 1 acre = 43,560 ft²
Visualization: An acre is roughly 208.7' × 208.7' (a square), or 43,560 sq ft in any shape.
Typical lot: A 0.25-acre suburban lot (~11,000 sq ft) might be 100' × 110' or 90' × 122'.
What is the average size of a home in the US?
2025 statistics:
- Median new single-family home: 2,261 sq ft (210 m²)
- Average new single-family home: 2,480 sq ft (230 m²)
- Existing homes (median): ~2,000 sq ft (186 m²)
Historical trend:
- 1973: 1,660 sq ft median
- 1990: 1,905 sq ft median
- 2007 (peak): 2,521 sq ft median
- 2009 (recession low): 2,135 sq ft median
- 2025: 2,261 sq ft median
Regional variation:
- Western US: Larger (2,400-2,600 sq ft avg)
- Southern US: Larger (2,300-2,500 sq ft avg)
- Northeastern US: Smaller (1,800-2,200 sq ft avg)
- Urban areas: Significantly smaller (1,200-1,800 sq ft avg)
How much does flooring cost per square foot?
Flooring costs vary widely by material and installation complexity:
Materials only (2025 US averages):
- Carpet: $1-5/sq ft
- Laminate: $2-5/sq ft
- Vinyl plank (LVP): $2-7/sq ft
- Engineered hardwood: $3-10/sq ft
- Solid hardwood: $5-15/sq ft
- Tile (ceramic): $1-10/sq ft
- Tile (porcelain): $3-15/sq ft
- Natural stone: $5-30/sq ft
Installed (material + labor):
- Carpet: $3-8/sq ft
- Laminate: $5-10/sq ft
- LVP: $6-12/sq ft
- Engineered hardwood: $8-18/sq ft
- Solid hardwood: $12-25/sq ft
- Tile: $10-30/sq ft
Total cost example: 1,000 sq ft of mid-grade engineered hardwood at $12/sq ft installed = $12,000
How do I calculate the square footage of my home?
For a rectangular home:
- Measure length and width of each room in feet
- Multiply length × width for each room (= sq ft)
- Sum all rooms
Example:
- Living room: 15' × 18' = 270 sq ft
- Kitchen: 12' × 14' = 168 sq ft
- Bedroom 1: 12' × 12' = 144 sq ft
- Bedroom 2: 10' × 11' = 110 sq ft
- Bathroom: 8' × 9' = 72 sq ft
- Total: 764 sq ft
For irregular spaces:
- Divide into rectangles, measure each, sum areas
- Or use a laser measure/measuring wheel
- Or use smartphone apps (RoomScan, MagicPlan) that use AR
What to include:
- Include: Heated/cooled living space, closets, hallways
- Exclude: Garage (listed separately), unfinished basement, attics, open porches
- Gray area: Finished basements often listed separately as "finished basement sq ft"
Professional measurement: Appraisers follow ANSI standards (Z765-2021) for consistent measurement.
Is the square foot an SI unit?
No, the square foot is not part of the International System of Units (SI). It belongs to imperial and US customary systems.
The SI unit for area is the square meter (m²).
However, square feet remain legally accepted for commerce in the US and are widely used alongside square meters in the UK, Canada, India, and many Commonwealth nations despite official metrication.
International context: When publishing for international audiences or scientific work, convert square feet to square meters (×0.0929).
Why are homes measured in square feet instead of square meters in the US?
Historical inertia: The US never fully metricated. Square footage has been standard in US real estate and construction for over a century.
Consumer familiarity: Americans intuitively understand home sizes in square feet. "2,000 square feet" is meaningful; "185 square meters" requires mental conversion.
Industry entrenchment: Building codes, zoning laws, construction standards, and appraisal methods all use square feet. Switching would require massive regulatory updates and retraining.
Resistance to change: Attempts to metricate the US in the 1970s (Metric Conversion Act of 1975) failed due to public and industry opposition.
Network effects: Since all comparable sales data is in square feet, realtors and buyers rely on it for valuation. Switching unilaterally would confuse comparisons.
Result: Square feet remain universal in US real estate, construction, and home improvement despite metric adoption in science, medicine, and manufacturing.
How many square feet do I need per person in a home?
Rough guidelines (varies by lifestyle, culture, family composition):
Minimum livable:
- 200-300 sq ft per person: Tight but functional (studio/small apartment)
- 400-600 sq ft per person: Comfortable (typical family home)
- 800-1,000+ sq ft per person: Spacious (luxury homes)
Examples:
- Single person: 400-800 sq ft (studio to 1-bedroom)
- Couple: 800-1,200 sq ft (1-2 bedrooms)
- Family of 3: 1,200-1,800 sq ft (2-3 bedrooms)
- Family of 4: 1,600-2,500 sq ft (3-4 bedrooms)
- Family of 5+: 2,000-3,500+ sq ft (4-5 bedrooms)
International comparison:
- US average: ~600-700 sq ft per person (2025)
- UK average: ~350-400 sq ft per person
- European Union: ~400-500 sq ft per person
- Japan: ~300-350 sq ft per person
- Hong Kong: ~150-200 sq ft per person (very dense)
Conversion Table: Square Mile to Square Foot
| Square Mile (mi²) | Square Foot (ft²) |
|---|---|
| 0.5 | 13,939,200 |
| 1 | 27,878,400 |
| 1.5 | 41,817,600 |
| 2 | 55,756,800 |
| 5 | 139,392,000 |
| 10 | 278,784,000 |
| 25 | 696,960,000 |
| 50 | 1,393,920,000 |
| 100 | 2,787,840,000 |
| 250 | 6,969,600,000 |
| 500 | 13,939,200,000 |
| 1,000 | 27,878,400,000 |
People Also Ask
How do I convert Square Mile to Square Foot?
To convert Square Mile to Square Foot, enter the value in Square Mile in the calculator above. The conversion will happen automatically. Use our free online converter for instant and accurate results. You can also visit our area converter page to convert between other units in this category.
Learn more →What is the conversion factor from Square Mile to Square Foot?
The conversion factor depends on the specific relationship between Square Mile and Square Foot. You can find the exact conversion formula and factor on this page. Our calculator handles all calculations automatically. See the conversion table above for common values.
Can I convert Square Foot back to Square Mile?
Yes! You can easily convert Square Foot back to Square Mile by using the swap button (⇌) in the calculator above, or by visiting our Square Foot to Square Mile converter page. You can also explore other area conversions on our category page.
Learn more →What are common uses for Square Mile and Square Foot?
Square Mile and Square Foot are both standard units used in area measurements. They are commonly used in various applications including engineering, construction, cooking, and scientific research. Browse our area converter for more conversion options.
For more area conversion questions, visit our FAQ page or explore our conversion guides.
Helpful Conversion Guides
Learn more about unit conversion with our comprehensive guides:
All Area Conversions
Other Area Units and Conversions
Explore other area units and their conversion options:
- Square Meter (m²) • Square Mile to Square Meter
- Square Kilometer (km²) • Square Mile to Square Kilometer
- Square Centimeter (cm²) • Square Mile to Square Centimeter
- Square Millimeter (mm²) • Square Mile to Square Millimeter
- Square Inch (in²) • Square Mile to Square Inch
- Square Yard (yd²) • Square Mile to Square Yard
- Acre (acre) • Square Mile to Acre
- Hectare (ha) • Square Mile to Hectare
Verified Against Authority Standards
All conversion formulas have been verified against international standards and authoritative sources to ensure maximum accuracy and reliability.
National Institute of Standards and Technology — Standards for area measurements
Last verified: December 3, 2025