Knot to Mile per hour Converter
Convert knots to miles per hour with our free online speed converter.
Quick Answer
1 Knot = 1.150779 miles per hour
Formula: Knot × conversion factor = Mile per hour
Use the calculator below for instant, accurate conversions.
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All conversion formulas on UnitsConverter.io have been verified against NIST (National Institute of Standards and Technology) guidelines and international SI standards. Our calculations are accurate to 10 decimal places for standard conversions and use arbitrary precision arithmetic for astronomical units.
Knot to Mile per hour Calculator
How to Use the Knot to Mile per hour Calculator:
- Enter the value you want to convert in the 'From' field (Knot).
- The converted value in Mile per hour will appear automatically in the 'To' field.
- Use the dropdown menus to select different units within the Speed category.
- Click the swap button (⇌) to reverse the conversion direction.
How to Convert Knot to Mile per hour: Step-by-Step Guide
Converting Knot to Mile per hour involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Knot = 1.150779 miles per hourExample Calculation:
Convert 60 knots: 60 × 1.150779 = 69.04677 miles per hour
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 speed units?
View all Speed conversions →What is a Knot and a Mile per hour?
The Mathematical Definition
1 Knot = 1 Nautical Mile per Hour
In SI Units: $$ 1 \text{ knot} = 1.852 \frac{\text{km}}{\text{h}} = 0.514444 \frac{\text{m}}{\text{s}} $$
In Imperial Units: $$ 1 \text{ knot} = 1.15078 \frac{\text{miles}}{\text{hour}} = 1.68781 \frac{\text{feet}}{\text{second}} $$
Why the Nautical Mile?
The nautical mile is not arbitrary—it's based on the Earth's geometry.
Definition: One nautical mile = one minute of latitude along a meridian.
The Math:
- Earth's circumference ≈ 40,075 km (at equator).
- 360 degrees × 60 minutes/degree = 21,600 minutes around the Earth.
- 40,075 km ÷ 21,600 = 1.855 km per minute of latitude.
- Standardized to exactly 1.852 km (1,852 meters).
Why This Matters: If you're at 40°N latitude and sail due north at 60 knots for 1 hour, you'll be at 41°N latitude. The math is perfect for navigation.
Knot vs. Statute Mile
| Unit | Length | Use | |------|--------|-----| | Nautical Mile | 6,076 feet (1,852 m) | Maritime, aviation navigation | | Statute Mile | 5,280 feet (1,609 m) | Land travel (cars, roads) | | Difference | 796 feet longer | Nautical mile is 15% longer |
Miles per hour (symbol: mph, MPH, or mi/h) is a unit of speed expressing the number of statute miles traveled in one hour.
Formula: Speed (mph) = Distance (miles) ÷ Time (hours)
Mathematical relationships:
- 1 mph = 1.60934 km/h (kilometers per hour)
- 1 mph = 0.44704 m/s (meters per second)
- 1 mph = 1.46667 ft/s (feet per second)
- 1 mph = 0.868976 knots
Key mental math: At 60 mph:
- You travel exactly 1 mile per minute
- You travel 88 feet per second
- You cover about 97 km/h
Why Miles per Hour Works
Intuitive scaling: The numbers align well with human driving speeds:
- Walking: 3-4 mph
- Residential driving: 25-35 mph
- Highway cruising: 60-70 mph
- Fast driving: 80-90 mph
Easy mental math at 60 mph: When driving 60 mph, distance and time calculations become trivial:
- 30 miles away = 30 minutes
- 90 miles away = 90 minutes (1.5 hours)
- 120 miles away = 120 minutes (2 hours)
This makes 60 mph a natural "reference speed" for American drivers.
Note: The Knot is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Mile per hour belongs to the imperial/US customary system.
History of the Knot and Mile per hour
: From Rope Knots to GPS
Ancient Navigation (Before 1500s)
Before the knot, sailors had no reliable way to measure speed. They used:
- Dead Reckoning: Estimating speed by watching foam, debris, or seaweed pass the ship.
- Guesswork: Experienced sailors "felt" the speed.
This led to massive navigation errors. Ships would miss islands, run aground, or get hopelessly lost.
The Chip Log Invention (1600s)
The chip log (or common log) revolutionized navigation.
Components:
- The Chip: A triangular wooden board weighted to float upright.
- The Log Line: A rope with knots tied at intervals of 47 feet 3 inches (14.4 meters).
- The Sandglass: A 28-second or 30-second timer.
The Process:
- Sailor throws the chip overboard from the stern.
- The chip stays relatively stationary in the water (drag keeps it in place).
- As the ship sails away, the log line unspools.
- Another sailor flips the sandglass.
- A third sailor counts the knots passing through his hands.
- When the sand runs out, they note the count: "7 knots!"
The Math: The knot spacing (47 ft 3 in) and timing (28-30 sec) were calibrated so that:
- 1 knot on the line = 1 nautical mile per hour of ship speed.
Example:
- If 7 knots passed in 30 seconds, the ship was traveling at 7 knots (7 nautical miles per hour).
Why "47 Feet 3 Inches"?
This seems random, but it's brilliant math:
- 1 nautical mile = 6,076 feet.
- 1 hour = 3,600 seconds.
- 30 seconds = 1/120 of an hour.
- 6,076 ÷ 120 = 50.63 feet.
Early sailors used 47 feet 3 inches (close enough) because it was easier to measure with the tools available.
Modern Standardization (1929)
The International Hydrographic Bureau standardized the nautical mile to exactly 1,852 meters in 1929. This fixed the knot at exactly 1.852 km/h.
Today:
- Ships use GPS and electronic speed logs.
- The chip log is obsolete, but the term "knot" remains universal.
Early 19th Century: Railway Origins
1820s-1830s Railway Boom: The first practical use of "miles per hour" appeared in British railway timetables in the 1820s and 1830s. Steam locomotives needed a standardized way to express speed.
Early Rail Speeds:
- 1825: Stockton & Darlington Railway averaged 15 mph (first passenger railway)
- 1830: Liverpool & Manchester Railway achieved 30 mph
- 1848: Railway speed records exceeded 60 mph
Why mph? Britain used statute miles for road distances, making mph the natural choice for rail speed measurement.
Mid-19th Century: Speed Regulation
1865: The "Red Flag Act" (UK): The Locomotive Act of 1865 limited self-propelled vehicles to:
- 4 mph in open country
- 2 mph in towns
- Required a person with a red flag walking ahead
This was the first national speed limit using mph, though it severely hampered early automotive development.
1896: Repeal and Freedom: The red flag requirement was repealed, allowing vehicles up to 14 mph.
Late 19th Century: Automotive Era Begins
1890s-1900s: Early Automobiles: As automobiles emerged, mph naturally became their speed measurement since roads already used miles for distance.
Early Auto Speeds:
- 1894: First automobile race averaged 15 mph (Paris-Rouen)
- 1906: Land speed record reached 127 mph
- 1920s: Typical cars cruised at 40-50 mph
20th Century: Speed Limits and Standards
1934: First US National Speed Limit (informal): Many states adopted 55-65 mph highway limits.
1974: National Maximum Speed Law (US): Energy crisis led Congress to mandate 55 mph nationwide to conserve fuel (1974-1987).
1987-1995: Speed Limits Raised: States regained control; limits increased to 65 mph on rural interstates.
1995-Present: Modern Speed Limits: Federal speed limit repealed. States set own limits:
- Rural interstates: 70-85 mph (Texas has 85 mph zones)
- Urban interstates: 55-70 mph
- Rural highways: 55-65 mph
- Urban streets: 25-45 mph
Global Metrication: The mph Holdouts
1960s-1970s: World Shifts to km/h: Most countries adopted the metric system and switched to km/h:
- Australia: 1974
- Canada: 1977
- Ireland: 2005
- South Africa: 1976
mph Survivors: Only a few countries still use mph:
- United States: All 50 states use mph exclusively
- United Kingdom: Road signs in mph (railways and aviation use km/h or knots)
- Some Caribbean nations: Remnants of British colonial influence
Common Uses and Applications: knots vs miles per hour
Explore the typical applications for both Knot (imperial/US) and Mile per hour (imperial/US) to understand their common contexts.
Common Uses for knots
1. Maritime Navigation
Why Knots?
- Chart Compatibility: Nautical charts use latitude/longitude. 1 knot = 1 minute of latitude per hour.
- Mental Math: Easy to calculate distance and time.
- Universal Standard: All ships worldwide use knots.
Example:
- "We're at 40°N, heading north at 30 knots."
- "In 2 hours, we'll be at 41°N." (30 knots × 2 hours = 60 nautical miles = 1 degree).
2. Aviation Navigation
Why Pilots Use Knots:
- International Standard: All air traffic control uses knots.
- Wind Reports: "Winds 270 at 15 knots" (from west at 15 knots).
- True Airspeed vs. Ground Speed: Pilots calculate wind correction using knots.
Example:
- True Airspeed: 450 knots (speed through air).
- Headwind: 50 knots.
- Ground Speed: 400 knots (speed over ground).
3. Meteorology
Wind Speed Reporting:
- Surface Winds: Reported in knots for marine forecasts.
- Upper-Level Winds: Jet stream speeds in knots (can reach 200+ knots).
- Hurricane Intensity: Measured in knots (64+ knots = hurricane).
4. Oceanography
Ocean Currents:
- Gulf Stream: Flows at 3-5 knots (fastest ocean current).
- Tidal Currents: Can reach 5-10 knots in narrow straits.
When to Use miles per hour
Road Transportation Standard
Speed Limits: All US road signs display mph:
- Speed Limit 25
- Speed Limit 55
- Speed Limit 70
Speedometers: All vehicles sold in the US have mph as primary scale:
- Digital displays: show mph
- Analog gauges: mph prominently displayed (km/h smaller, if present)
Traffic Enforcement:
- Speed cameras calibrated in mph
- Radar guns measure mph
- Tickets written in mph ("45 mph in a 30 mph zone")
Weather Forecasting
Wind Speed: US weather reports use mph:
- "Winds 10-15 mph"
- "Gusts up to 40 mph"
- "Sustained winds of 75 mph" (hurricane)
Severe Weather Warnings:
- High wind warning: sustained winds 40+ mph
- Hurricane watch: sustained winds 74+ mph expected
- Tornado warning: rotational winds estimated in mph
Weather Apps: US apps default to mph for wind speed.
Aviation Context (Mixed Use)
Airspeed Indicators: Pilots see:
- Knots (nautical miles per hour) - primary in aviation
- Some general aviation planes show mph
Ground Speed: GPS and flight computers often display:
- Knots for professional aviation
- mph option available for private pilots
Weather Briefings: Aviation weather uses knots, but surface winds at some small airports reported in mph.
Sports Performance Measurement
Baseball Pitch Tracking:
- MLB stadiums display pitch speed in mph on scoreboards
- "95 mph fastball"
- Scouting reports use mph
Racing:
- NASCAR: "Averaging 185 mph for the lap"
- Drag racing: "Trap speed 325 mph"
- Land speed records: measured in mph
Speed Skating, Cycling: In US competitions, sometimes reported in mph alongside metric.
Everyday Distance/Time Calculations
Trip Planning: Americans mentally calculate travel time using mph:
- "It's 180 miles, so 3 hours at 60 mph"
- "I average 70 mph on the highway, so 350 miles takes 5 hours"
Fuel Economy Relationship: MPG (miles per gallon) and mph are connected:
- Highway MPG ratings assume 55-65 mph
- Fuel economy drops significantly above 70 mph
Real Estate: Property distance to amenities:
- "20 minutes at 45 mph = about 15 miles"
Additional Unit Information
About Knot (kn)
Why do planes and ships use knots instead of mph?
Historical Reason:
- Early aviation borrowed from maritime tradition.
- Pilots and sailors both navigate using latitude/longitude.
Practical Reason:
- 1 knot = 1 minute of latitude per hour makes navigation calculations trivial.
- Using mph would require constant conversion (1 degree latitude ≈ 69 statute miles).
Example:
- Knots: "Flying north at 60 knots for 1 hour = 1 degree north."
- mph: "Flying north at 69 mph for 1 hour = 1 degree north." (Awkward!)
Is saying "knots per hour" correct?
No! This is a common mistake.
Wrong: "The ship is doing 20 knots per hour." Right: "The ship is doing 20 knots."
Why?
- Knot already means "nautical miles per hour."
- Saying "knots per hour" is like saying "miles per hour per hour" (which is acceleration, not speed).
How do I convert knots to mph mentally?
Quick Method: Add 15%
Steps:
- Take the knot value (e.g., 40 knots).
- Calculate 10%: 40 × 0.1 = 4.
- Calculate 5% (half of 10%): 4 ÷ 2 = 2.
- Add them: 40 + 4 + 2 = 46 mph.
- (Actual: 46.03 mph—very close!)
What is the fastest speed ever recorded in knots?
Water Speed Record:
- 276 knots (317 mph) by Spirit of Australia (1978).
- Jet-powered hydroplane.
Air Speed Record (Manned):
- 1,905 knots (2,193 mph, Mach 3.3) by SR-71 Blackbird.
Wind Speed Record:
- 253 knots (291 mph) measured during Tropical Cyclone Olivia (1996) in Australia.
Do cars ever use knots?
No. Cars use:
- mph (miles per hour) in the US, UK.
- km/h (kilometers per hour) everywhere else.
Knots are exclusively for maritime and aviation use.
Why is a nautical mile longer than a statute mile?
Statute Mile: Based on Roman measurements (1,000 paces = 5,280 feet). Arbitrary.
Nautical Mile: Based on Earth's geometry (1 minute of latitude = 6,076 feet). Scientific.
The nautical mile is 15% longer because it's tied to the planet's actual size.
How fast is the wind in a hurricane?
Hurricane Categories (Saffir-Simpson Scale):
| Category | Wind Speed (Knots) | Wind Speed (mph) | Damage | |----------|-------------------|------------------|--------| | Tropical Storm | 34-63 knots | 39-73 mph | Minimal | | Category 1 | 64-82 knots | 74-95 mph | Some damage | | Category 2 | 83-95 knots | 96-110 mph | Extensive damage | | Category 3 | 96-112 knots | 111-129 mph | Devastating | | Category 4 | 113-136 knots | 130-156 mph | Catastrophic | | Category 5 | 137+ knots | 157+ mph | Total destruction |
Threshold: A tropical storm becomes a hurricane at 64 knots (74 mph).
What is a "gale" in knots?
Beaufort Wind Scale:
| Force | Name | Wind Speed (Knots) | Conditions | |-------|------|-------------------|------------| | 7 | Near Gale | 28-33 | Difficult to walk | | 8 | Gale | 34-40 | Twigs break off trees | | 9 | Strong Gale | 41-47 | Roof damage | | 10 | Storm | 48-55 | Trees uprooted | | 11 | Violent Storm | 56-63 | Widespread damage | | 12 | Hurricane | 64+ | Catastrophic |
Gale Warning: Issued when winds are expected to reach 34-47 knots.
How fast is Mach 1 in knots?
Mach 1 (speed of sound) varies with temperature and altitude.
At Sea Level (59°F):
- Mach 1 ≈ 661 knots (761 mph, 1,225 km/h).
At 35,000 feet (typical cruise altitude):
- Mach 1 ≈ 573 knots (659 mph, 1,062 km/h).
Concorde Cruise Speed:
- Mach 2.0 ≈ 1,150 knots (1,323 mph).
Conversion Table: Knot to Mile per hour
| Knot (kn) | Mile per hour (mph) |
|---|---|
| 0.5 | 0.575 |
| 1 | 1.151 |
| 1.5 | 1.726 |
| 2 | 2.302 |
| 5 | 5.754 |
| 10 | 11.508 |
| 25 | 28.77 |
| 50 | 57.539 |
| 100 | 115.078 |
| 250 | 287.695 |
| 500 | 575.39 |
| 1,000 | 1,150.779 |
People Also Ask
How do I convert Knot to Mile per hour?
To convert Knot to Mile per hour, enter the value in Knot in the calculator above. The conversion will happen automatically. Use our free online converter for instant and accurate results. You can also visit our speed converter page to convert between other units in this category.
Learn more →What is the conversion factor from Knot to Mile per hour?
The conversion factor depends on the specific relationship between Knot and Mile per hour. 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 Mile per hour back to Knot?
Yes! You can easily convert Mile per hour back to Knot by using the swap button (⇌) in the calculator above, or by visiting our Mile per hour to Knot converter page. You can also explore other speed conversions on our category page.
Learn more →What are common uses for Knot and Mile per hour?
Knot and Mile per hour are both standard units used in speed measurements. They are commonly used in various applications including engineering, construction, cooking, and scientific research. Browse our speed converter for more conversion options.
For more speed conversion questions, visit our FAQ page or explore our conversion guides.
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⚖️ Metric vs Imperial
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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 speed and velocity measurements
Last verified: December 3, 2025