Milliliter to Gallon (US) Converter
Convert milliliters to US gallons with our free online volume converter.
Quick Answer
1 Milliliter = 0.000264 US gallons
Formula: Milliliter × conversion factor = Gallon (US)
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.
Milliliter to Gallon (US) Calculator
How to Use the Milliliter to Gallon (US) Calculator:
- Enter the value you want to convert in the 'From' field (Milliliter).
- The converted value in Gallon (US) will appear automatically in the 'To' field.
- Use the dropdown menus to select different units within the Volume category.
- Click the swap button (⇌) to reverse the conversion direction.
How to Convert Milliliter to Gallon (US): Step-by-Step Guide
Converting Milliliter to Gallon (US) involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Milliliter = 0.000264172 US gallonsExample Calculation:
Convert 10 milliliters: 10 × 0.000264172 = 0.00264172 US gallons
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 volume units?
View all Volume conversions →What is a Milliliter and a Gallon (US)?
The milliliter (symbol: mL or ml) is a unit of volume equal to exactly one-thousandth of a liter (1/1000 L or 0.001 L). Critically, 1 milliliter equals exactly 1 cubic centimeter (1 cm³ or 1 cc).
The milliliter is part of the International System of Units (SI) and uses the metric prefix "milli-" meaning one-thousandth (from Latin mille, "thousand").
Mathematical Relationships
1 milliliter equals:
- 0.001 liters (L)
- 1 cubic centimeter (cm³ or cc) exactly
- 0.000001 cubic meters (m³)
- 0.033814 US fluid ounces (fl oz)
- 0.035195 UK fluid ounces (imperial)
- 0.202884 teaspoons (tsp)
- 0.067628 tablespoons (tbsp)
Key water relationship:
- 1 mL of water weighs 1 gram (at 4°C, maximum density)
This elegant relationship makes metric conversions trivial for water-based solutions.
Milliliter = Cubic Centimeter (cc)
Perfect equivalence: 1 mL = 1 cm³ = 1 cc (all three are identical)
Why this matters:
- Medical syringes often marked in "cc" (cubic centimeters) = milliliters
- Engine displacement: "2000 cc engine" = 2000 mL = 2.0 L
- Laboratory glassware uses both mL and cm³ interchangeably
- A cube with 1 cm sides (1 cm × 1 cm × 1 cm) holds exactly 1 mL
Symbol variations:
- mL (preferred in scientific publishing—avoids confusion with number "1")
- ml (common in everyday use)
- cc (common in medical and automotive contexts)
Why Milliliters?
While the liter is the base metric unit for volume, milliliters are more practical for everyday measurements:
Perfect human scale: Most cooking ingredients, medications, and beverage servings fall into the 5-500 mL range, avoiding decimals.
Avoids decimal confusion: "250 milliliters of milk" is clearer than "0.25 liters of milk" for most people.
Universal adoption: Used in 195+ countries for recipes, medicine, beverages, and laboratory work.
The US gallon is a unit of volume in the United States customary measurement system. Since the Mendenhall Order of 1893 and confirmed by the 1959 international yard and pound agreement, one US gallon has been defined as exactly 231 cubic inches, which equals precisely 3.785411784 liters.
The US gallon is denoted by the symbol gal or sometimes gal US to distinguish it from the Imperial gallon. In everyday contexts, Americans simply say "gallon" with the US definition understood implicitly.
The gallon divides into smaller units following consistent relationships:
- 1 gallon = 4 quarts (qt)
- 1 gallon = 8 pints (pt)
- 1 gallon = 16 cups (c)
- 1 gallon = 128 fluid ounces (fl oz)
- 1 gallon = 231 cubic inches (cu in)
Unlike the metric system's clean decimal relationships (1 liter = 1,000 milliliters), the US gallon uses fractional divisions rooted in historical measurement traditions. This creates the complex but familiar relationships Americans learn: 4 quarts to a gallon, 2 pints to a quart, 2 cups to a pint.
Note: The Milliliter is part of the metric (SI) system, primarily used globally in science and trade. The Gallon (US) belongs to the imperial/US customary system.
History of the Milliliter and Gallon (US)
French Revolution: Birth of the Liter (1795)
Metric System Creation: The milliliter's story begins with the French Revolution's creation of the liter in 1795.
Water-Based Definition: One liter was originally defined as the volume occupied by one kilogram of pure water at maximum density (approximately 4°C or 39°F).
Elegant Interconnection:
- 1 liter of water = 1 kilogram = 1,000 grams
- 1 milliliter of water = 1 gram
- 1 milliliter = 1 cubic centimeter
This made the metric system beautifully self-consistent—volume, mass, and spatial dimensions all linked through water.
Etymology: The word "liter" comes from the obsolete French unit "litron," which was derived from Medieval Latin "litra" (a unit of mass).
The Medieval Litron: A Pre-Metric Precursor
Before the French Revolution standardized the liter, the "litron" was a measure for grain and salt.
- The Royal Litron: In the 17th century, the litron was roughly equivalent to 0.81 liters. However, because it was often measured using wooden boxes that could warp with humidity, the volume of a litron changed with the seasons.
- The Tax Man's Litron: French peasants often had to pay their taxes in litrons of grain. This created a massive incentive for the crown to "expand" the litron while the peasants tried to "shrink" it, a measurement war that only ended with the precision of the metric milliliter.
The Milliliter in 19th Century Pharmacy
As "Apothecary" shops evolved into modern pharmacies, the "Drop" became a liability.
- The Graduated Minim: Pharmacists used a 1-minim dropper, which was supposed to be 1/60th of a fluid dram. However, because the viscosity of oils versus tinctures resulted in different drop sizes, pharmacists pushed for the adoption of the milliliter as the only legally defensible unit for liquid drugs.
The Prefix "Milli-"
Latin Origin: "Milli-" comes from the Latin "mille" meaning "thousand."
Meaning: Milli- means one-thousandth (1/1000 or 0.001).
Other milli- units:
- Millimeter: 1/1000 meter
- Milligram: 1/1000 gram
- Millisecond: 1/1000 second
- Milliliter: 1/1000 liter
19th Century: Global Spread
1875: Metre Convention: The Treaty of the Metre established international cooperation on measurement standards. The liter (and milliliter) became recognized internationally.
Scientific Adoption: Laboratories worldwide embraced milliliters for precise liquid measurements, replacing inconsistent local units.
Medical Use: By the late 1800s, medicine had standardized on milliliters (or cubic centimeters/cc) for drug dosages and liquid medicines.
1901: Redefinition
Precision Refinement: In 1901, the liter was redefined as the volume of 1 kg of pure water at maximum density under standard atmospheric pressure. This made the liter slightly larger than 1 cubic decimeter (by about 28 parts per million).
1964: Modern Definition
CIPM Decision: The International Committee for Weights and Measures (CIPM) redefined the liter as exactly one cubic decimeter (1 dm³).
Impact on milliliters: 1 milliliter = exactly 1 cubic centimeter (1 cm³), eliminating any tiny discrepancy.
Current definition: The milliliter is now purely geometric—the volume of a cube with 1 cm sides—rather than water-based.
The gallon represents one of the oldest volume measurements still in common use, with roots stretching back over a millennium.
Roman and Medieval Origins: The word "gallon" derives from the Old Northern French galon, related to medieval Latin galleta or galletum (a measure of wine). Multiple gallon definitions existed simultaneously in medieval England: the wine gallon, ale gallon, and corn gallon, each sized differently for their respective commodities.
Wine Gallon Standardization: In 1707, during the reign of Queen Anne, England standardized the wine gallon at exactly 231 cubic inches. This became the legal definition for measuring wine and spirits throughout the British Empire. The wine gallon was chosen because it represented the volume of a cylinder 7 inches in diameter and 6 inches high—a practical size for cooperage (barrel-making).
American Adoption: After independence, the United States retained the English wine gallon as its standard liquid measure. The Weights and Measures Act of 1836 legally established 231 cubic inches as the US gallon definition, maintaining continuity with colonial-era commerce.
The Queen Anne Wine Gallon: A Practical Standard
The choice of 231 cubic inches was actually a compromise between different historical wine vessels.
- The Cylinder Math: Queen Anne's mathematicians defined the gallon as a cylinder 7 inches in diameter and 6 inches deep (using π as 22/7). This made the math easy for merchants at the time to verify with a simple ruler.
- The Conflict: Before this standardization, merchants were constantlly fighting over whose "gallon" was bigger. By decreeing the "Wine Gallon" as the national standard, Queen Anne helped stabilize the British economy—and ironically, the American economy that followed.
Common Uses and Applications: milliliters vs US gallons
Explore the typical applications for both Milliliter (metric) and Gallon (US) (imperial/US) to understand their common contexts.
Common Uses for milliliters
Medicine and Pharmacology
Prescription Medications: Liquid medications measured in milliliters:
- Antibiotics: "Take 10 mL twice daily"
- Cough syrup: "Take 15 mL every 4-6 hours"
- Pain relievers: "Give 5 mL per dose for children"
Dosing Precision: Milliliters allow accurate dosing:
- Pediatric doses often require precision to 0.5 mL
- Adult doses typically 5-30 mL range
- Measuring spoons or syringes marked in mL
IV Fluids: Hospital IV bags measured in mL:
- Saline drip: 1,000 mL bag, infused over hours
- Medication delivery: 50-250 mL piggyback bags
- Fluid intake/output: tracked in mL for patient monitoring
Cooking Worldwide
Global Recipe Standard: Most countries use milliliters for liquid ingredients:
- "Add 250 mL milk"
- "Mix in 30 mL soy sauce"
- "Drizzle with 45 mL olive oil"
Kitchen Measuring Tools:
- Liquid measuring cups: marked in mL (and fluid ounces in US)
- Measuring spoons: 1.25 mL, 2.5 mL, 5 mL, 15 mL
- Kitchen scale with liquid mode: measures mL for water-based liquids
Precision Baking: Professional bakers prefer milliliters for consistency:
- Eliminates meniscus reading errors
- Repeatable results
- Easy scaling (double recipe = double all mL measurements)
Beverage Industry
Product Labeling: Beverages worldwide labeled in milliliters:
- "Contents: 355 mL (12 fl oz)"
- "Serving size: 250 mL"
- "Servings per container: 4 (1,000 mL bottle)"
Alcohol Content: "Standard drink" defined in mL in many countries:
- Australia: 10 mL pure alcohol = 1 standard drink
- UK: 8 mL (10g) pure alcohol = 1 unit
- US: 14 mL (17.7g) pure alcohol = 1 standard drink
Bartending: Cocktail recipes use milliliters:
- Jigger: 30 mL (1 oz) or 45 mL (1.5 oz)
- Recipes: "45 mL vodka, 15 mL lime juice, 10 mL simple syrup"
Laboratory Science
Chemistry: Milliliters essential for chemical reactions:
- Titrations: measuring acid/base volumes to 0.1 mL
- Solution preparation: "Dissolve in 500 mL solvent"
- Concentration: moles per liter (mol/L or M)
Biology: Cell culture and biological assays:
- Cell culture media: 10-50 mL per flask
- PCR reactions: measured in microliters (µL), 1 µL = 0.001 mL
- Biological samples: typically 0.5-5 mL volumes
Physics: Density measurements use mL:
- Density = mass (grams) ÷ volume (milliliters) = g/mL
- Water: 1 g/mL at 4°C
- Alcohol: 0.79 g/mL
- Mercury: 13.6 g/mL
Cosmetics and Personal Care
Product Packaging: Cosmetics labeled in milliliters:
- Perfume: 30 mL, 50 mL, 100 mL bottles
- Foundation: 30-50 mL bottles
- Shampoo: 250 mL, 500 mL, 1,000 mL bottles
- Travel sizes: typically 100 mL or less (TSA limit)
When to Use US gallons
Automotive Fuel Economy and Travel
Americans evaluate vehicles primarily by miles per gallon (MPG), calculating range as: gallons × MPG = miles of range. A 15-gallon tank at 30 MPG provides 450 miles of range. This gallon-centric thinking influences vehicle purchases, trip planning, and daily driving decisions.
EPA fuel economy ratings appear on every new car: city MPG, highway MPG, and combined MPG. Buyers compare vehicles: "This sedan gets 35 MPG, but the SUV only gets 22 MPG—over a year, that's X extra gallons costing $Y more."
Fuel tracking apps and vehicle computers display gallons used, average MPG, and cost per gallon. Many drivers mentally track "dollars per gallon times gallons per tank" to estimate monthly fuel budgets: 4 tanks × 14 gallons × $3.50 = $196/month.
Residential Water Supply and Wells
Private wells measure output in gallons per minute (GPM), indicating how much water the well can supply:
- Poor well: 1-3 GPM (enough for 1-2 people with conservation)
- Adequate well: 5-6 GPM (typical household needs)
- Good well: 10+ GPM (supports larger family, lawn irrigation)
Well recovery rate (how fast the well refills after pumping) measures in gallons. A well might hold 200 gallons in the casing, recover at 5 GPM, meaning after draining, it refills 300 gallons per hour.
Municipal water supply capacity scales to millions of gallons daily (MGD). A small town might have 2 MGD capacity, serving 5,000 residents at 400 gallons per person per day (including commercial and industrial use).
Commercial and Industrial Processes
Manufacturing processes specify volumes in gallons for liquids:
Food processing:
- Beverage bottling lines: 500-2,000 gallons per hour throughput
- Dairy pasteurization: Batch sizes of 1,000-5,000 gallons
- Brewing: Fermentation tanks 100-10,000 gallons (microbreweries to major producers)
Chemical manufacturing:
- Reaction vessels: 500-20,000 gallon capacity
- Storage tanks: 10,000-1,000,000 gallons
- Mixing operations: Recipe calls for X gallons of component A, Y gallons of component B
Wastewater treatment:
- Municipal treatment plant: 1-50 million gallons per day (MGD) capacity
- Holding tanks: 100,000-1,000,000 gallons
- Treatment chemical dosing: Gallons of chemical per million gallons of wastewater
Additional Unit Information
About Gallon (US) (gal)
How many liters are in a US gallon?
One US gallon equals exactly 3.785411784 liters. This precise relationship was established through the 1959 international yard and pound agreement, which defined the inch as exactly 2.54 centimeters. Since the US gallon equals 231 cubic inches, the liter conversion calculates exactly.
Quick conversions:
- 1 US gallon = 3.785 liters (rounded)
- 5 gallons = 18.927 liters
- 10 gallons = 37.854 liters
Reverse conversion: 1 liter = 0.264172 US gallons
- 1 liter ≈ 0.26 gallons (roughly 1/4 gallon)
- 4 liters = 1.057 gallons (slightly more than 1 gallon)
- 10 liters = 2.642 gallons
Practical approximation: For everyday estimates, remember 4 liters ≈ 1 gallon (5% high). A 2-liter soda bottle is roughly half a gallon (actually 0.53 gallons). More precisely, 3.8 liters ≈ 1 gallon gives results within 0.4%.
How many quarts are in a US gallon?
There are exactly 4 quarts in 1 US gallon. This relationship is definitional—the quart (quarter gallon) derives its name from being one-fourth of a gallon.
Gallon subdivisions:
- 1 gallon = 4 quarts
- 1 gallon = 8 pints (2 pints per quart)
- 1 gallon = 16 cups (2 cups per pint)
- 1 gallon = 128 fluid ounces (8 fl oz per cup)
Converting gallons to quarts: Multiply by 4
- 2.5 gallons = 10 quarts
- 5 gallons = 20 quarts
Converting quarts to gallons: Divide by 4
- 12 quarts = 3 gallons
- 10 quarts = 2.5 gallons
- 3 quarts = 0.75 gallons
These consistent relationships make cooking and liquid measurement straightforward: doubling a recipe that calls for 2 quarts means using 1 gallon.
Is a US gallon the same as an Imperial gallon?
No—the US gallon and Imperial gallon are different volumes. The US gallon is approximately 83% the size of an Imperial gallon, creating significant differences in measurements.
US gallon: 231 cubic inches = 3.785 liters Imperial gallon: 277.42 cubic inches = 4.546 liters Difference: Imperial gallon is ~20% larger (1.201× the US gallon)
Conversion:
- 1 Imperial gallon = 1.201 US gallons
- 1 US gallon = 0.833 Imperial gallons
Why it matters:
Fuel economy: UK vehicle rated at 40 Imperial MPG equals 33.3 US MPG. The Imperial gallon is larger, so going 40 miles on that bigger gallon means worse efficiency than 40 US MPG.
Recipes: British recipe calling for "1 gallon milk" means 4.546 liters, but Americans using US gallons would only use 3.785 liters—nearly 20% less, potentially ruining the recipe.
Shipping/commerce: Ordering "1000 gallons" internationally requires specifying which gallon to avoid receiving 833 or 1,201 gallons instead.
Historical note: Both countries used the wine gallon (231 cu in) until 1824, when Britain adopted the Imperial system with a larger gallon based on 10 pounds of water. The US retained the smaller wine gallon, creating the divergence.
Why do Americans use gallons instead of liters?
Americans use gallons instead of liters primarily due to infrastructure investment, cultural familiarity, and regulatory inertia—not because gallons offer any technical advantage.
Infrastructure costs: Converting to liters would require replacing or recalibrating:
- 150,000+ gas station pumps ($10,000-50,000 each to replace)
- Millions of fuel tanks, storage systems, and delivery trucks calibrated in gallons
- Industrial equipment, mixing systems, and process controls based on gallons
- Signage, labeling, and retail systems throughout supply chains
Estimated total cost: Tens of billions of dollars across all affected industries.
Cultural familiarity: Americans instinctively understand gallons from childhood:
- "Miles per gallon" is the universal fuel efficiency metric
- Milk comes in gallon jugs
- Paint buckets hold 1 or 5 gallons
- Pool capacity measures in thousands of gallons
Most Americans can't visualize a liter intuitively—"3.785 liters" means nothing, while "1 gallon" immediately conveys a specific, familiar quantity.
Regulatory flexibility: The 1975 Metric Conversion Act made metric "preferred" but voluntary. Without mandatory conversion deadlines or enforcement, industries continued using gallons. Attempts to require metric labeling on gas pumps faced fierce public resistance in the 1990s.
Partial adoption: The US uses liters in some contexts—2-liter soda bottles, engine displacement (2.0L engine), alcoholic beverages (750ml wine bottles). This creates a hybrid system where both units coexist, reducing pressure for full conversion.
Economic reality: Changing would be expensive, disruptive, and unpopular, with no clear benefit justifying the cost. Gallons work perfectly well for domestic commerce, and international trade already accommodates multiple measurement systems.
How much does a gallon of water weigh?
A US gallon of water weighs approximately 8.34 pounds (3.78 kg) at room temperature (70°F/21°C). This weight varies slightly with temperature as water density changes.
Temperature effects:
- 32°F (0°C, nearly freezing): 8.34 lbs per gallon
- 39.2°F (4°C, maximum density): 8.35 lbs per gallon
- 70°F (21°C, room temperature): 8.33 lbs per gallon
- 200°F (93°C, hot): 8.16 lbs per gallon
- 212°F (100°C, boiling): 8.00 lbs per gallon
Practical rule: "A gallon of water weighs about 8.3 pounds" works well for most purposes.
Related conversions:
- 1 cubic foot of water = 7.48 gallons = 62.4 pounds
- 1 quart of water = 2.08 pounds
- 1 pint of water = 1.04 pounds (origin of "a pint's a pound the world around")
Why it matters:
Weight calculations: A 500-gallon hot tub holds 4,170 pounds of water (over 2 tons)—critical for deck structural load calculations.
Shipping costs: 55-gallon drum of water weighs 458 lbs plus container weight, affecting freight costs and handling requirements.
Vehicle loading: Carrying 15 gallons of water in a car adds 125 lbs, measurably affecting fuel economy and handling.
Emergency preparedness: Storing 14 gallons of water per person (2-week supply) equals 117 lbs per person, requiring sturdy shelving.
What's the difference between liquid gallons and dry gallons?
The US liquid gallon (231 cubic inches = 3.785 liters) is the standard gallon used today for all liquids—gasoline, milk, paint, water, chemicals, etc.
The US dry gallon (268.8 cubic inches = 4.405 liters) was historically used for measuring dry goods like grain, fruit, and vegetables. It's approximately 1.16 times larger than the liquid gallon.
Current usage: The dry gallon is essentially obsolete. Modern commerce measures dry goods by weight (pounds, kilograms) rather than volume. You'll never encounter dry gallons in everyday life—farmers sell grain by the bushel (8 dry gallons, but nobody thinks of it this way) or by weight.
Why the difference existed: Different gallon sizes accommodated measuring methods. Liquids fill containers completely without air gaps, while dry goods like grain have air spaces between kernels. The larger dry gallon compensated for this, attempting to standardize weight-to-volume relationships.
Today: When anyone says "gallon" without qualifier, they always mean liquid gallon. Dry gallon survives only in historical documents and archaic legal definitions. Even the produce section of supermarkets prices fruits and vegetables by the pound, not by dry volume.
How many ounces are in a gallon?
There are exactly 128 fluid ounces in 1 US gallon. This relationship derives from the gallon's subdivisions:
- 1 gallon = 4 quarts
- 1 quart = 32 fluid ounces
- Therefore: 4 × 32 = 128 fluid ounces per gallon
Alternative path:
- 1 gallon = 16 cups
- 1 cup = 8 fluid ounces
- Therefore: 16 × 8 = 128 fluid ounces per gallon
Common conversions:
- Half-gallon = 64 fluid ounces (2 quarts)
- Quarter-gallon = 32 fluid ounces (1 quart)
- 1 gallon = 128 fl oz
Beverage bottles:
- 2-liter soda = 67.6 fl oz (about half a gallon)
- 20 oz bottle = 0.156 gallons
- 32 oz (quart) = 0.25 gallons
- 64 oz (half-gallon) = 0.5 gallons
- 128 oz = 1 gallon
Daily water intake: Health recommendations often suggest "eight 8-ounce glasses per day" = 64 fluid ounces = half a gallon. Some trainers recommend "a gallon a day" (128 oz) for people exercising heavily, though this may be excessive for sedentary individuals.
Important: Fluid ounces measure volume. Don't confuse with ounces of weight. A fluid ounce of water weighs approximately 1.04 ounces (weight), but a fluid ounce of honey weighs about 1.5 ounces (weight) due to different densities.
How do you calculate pool capacity in gallons?
Pool capacity calculation depends on shape. Use these formulas for accurate gallon measurements:
Rectangular Pool: Length (ft) × Width (ft) × Average Depth (ft) × 7.5 = Gallons
Example: 20 ft × 40 ft × 5 ft × 7.5 = 30,000 gallons
Round Pool: Diameter (ft) × Diameter (ft) × Average Depth (ft) × 5.9 = Gallons
Example: 24 ft diameter × 24 ft × 4 ft × 5.9 = 13,594 gallons
Oval Pool: Long Diameter (ft) × Short Diameter (ft) × Average Depth (ft) × 5.9 = Gallons
Example: 30 ft × 15 ft × 4.5 ft × 5.9 = 11,933 gallons
Kidney/Irregular Shapes: Break into rectangular and circular sections, calculate each, sum total. Or multiply surface area (sq ft) × average depth × 7.5.
Average depth calculation: For pools with sloped bottoms: (Shallow End Depth + Deep End Depth) ÷ 2
Example: 3 ft shallow, 8 ft deep: (3 + 8) ÷ 2 = 5.5 ft average depth
Why accuracy matters:
- Chemical dosing based on gallons: 1 lb chlorine per 10,000 gallons
- Incorrect volume leads to under/over-treatment
- Filter and pump sizing depends on gallons
- Heating costs calculated from gallon volume
Verification: Fill the pool with a water meter running, or hire a pool professional to measure during initial filling. Record the exact capacity permanently—don't recalculate each season.
Can you mix gallons and quarts in calculations?
Yes, but convert to a common unit to avoid errors. Gallons and quarts can be added, subtracted, and converted, but keeping them in mixed notation (2 gallons 3 quarts) during calculations invites mistakes.
Best practice: Convert everything to decimal gallons:
- 2 gallons 3 quarts = 2 + (3÷4) = 2.75 gallons
- 1 gallon 2 quarts = 1 + (2÷4) = 1.5 gallons
- Sum: 2.75 + 1.5 = 4.25 gallons
Alternative: Convert to quarts, calculate, convert back:
- 2 gallons 3 quarts = 8 + 3 = 11 quarts
- 1 gallon 2 quarts = 4 + 2 = 6 quarts
- Sum: 11 + 6 = 17 quarts = 4 gallons 1 quart = 4.25 gallons
Adding mixed notation directly (error-prone):
- 2 gal 3 qt + 1 gal 2 qt = 3 gal 5 qt
- But 5 qt = 1 gal 1 qt, so convert: 3 gal + 1 gal 1 qt = 4 gal 1 qt = 4.25 gallons
Kitchen measurements: Recipes might call for "1 gallon plus 1 quart milk." Convert immediately: 1.25 gallons simplifies calculations and reduces measurement errors.
What's the origin of "231 cubic inches" for a gallon?
The US gallon's definition as 231 cubic inches traces back to England's 1707 wine gallon standardization under Queen Anne. This specific number wasn't arbitrary—it represented the volume of a cylinder 7 inches in diameter and 6 inches high, a practical size for wine casks in cooperage (barrel-making).
Mathematical basis:
- Cylinder volume = π × radius² × height
- 7-inch diameter = 3.5-inch radius
- π × (3.5)² × 6 = π × 12.25 × 6 = 230.91 cubic inches
Rounded to 231 cubic inches for legal simplicity, this definition proved remarkably durable. When the United States gained independence, it retained this British standard.
Why this size? The dimensions reflected practical container manufacturing. Coopers (barrel makers) could reliably produce uniform containers using these proportions. The gallon represented a convenient trade unit—large enough for efficient commerce, small enough for individual transactions.
Alternative gallons: Before 1707, England used multiple gallon definitions simultaneously—ale gallon (282 cu in), wine gallon (231 cu in), corn gallon (268.8 cu in). Queen Anne's standardization chose the wine gallon, establishing 231 cubic inches as the official liquid measure throughout the British Empire.
Modern persistence: The 231 cubic inch definition survived Britain's 1824 Imperial reform (which created a larger 277.42 cu in gallon). Americans kept the colonial-era 231 cu in gallon, maintaining continuity with established commerce. Today, this 300-year-old measurement remains legally enshrined in US law, converted precisely to 3.785411784 liters through the 1959 international agreement.
Conversion Table: Milliliter to Gallon (US)
| Milliliter (mL) | Gallon (US) (gal) |
|---|---|
| 0.5 | 0 |
| 1 | 0 |
| 1.5 | 0 |
| 2 | 0.001 |
| 5 | 0.001 |
| 10 | 0.003 |
| 25 | 0.007 |
| 50 | 0.013 |
| 100 | 0.026 |
| 250 | 0.066 |
| 500 | 0.132 |
| 1,000 | 0.264 |
People Also Ask
How do I convert Milliliter to Gallon (US)?
To convert Milliliter to Gallon (US), enter the value in Milliliter in the calculator above. The conversion will happen automatically. Use our free online converter for instant and accurate results. You can also visit our volume converter page to convert between other units in this category.
Learn more →What is the conversion factor from Milliliter to Gallon (US)?
The conversion factor depends on the specific relationship between Milliliter and Gallon (US). 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 Gallon (US) back to Milliliter?
Yes! You can easily convert Gallon (US) back to Milliliter by using the swap button (⇌) in the calculator above, or by visiting our Gallon (US) to Milliliter converter page. You can also explore other volume conversions on our category page.
Learn more →What are common uses for Milliliter and Gallon (US)?
Milliliter and Gallon (US) are both standard units used in volume measurements. They are commonly used in various applications including engineering, construction, cooking, and scientific research. Browse our volume converter for more conversion options.
For more volume conversion questions, visit our FAQ page or explore our conversion guides.
Helpful Conversion Guides
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📚 How to Convert Units
Step-by-step guide to unit conversion with practical examples.
🔢 Conversion Formulas
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⚖️ Metric vs Imperial
Understand the differences between measurement systems.
⚠️ Common Mistakes
Learn about frequent errors and how to avoid them.
All Volume Conversions
Other Volume Units and Conversions
Explore other volume units and their conversion options:
- Liter (L) • Milliliter to Liter
- Cubic meter (m³) • Milliliter to Cubic meter
- Gallon (UK) (gal) • Milliliter to Gallon (UK)
- Quart (qt) • Milliliter to Quart
- Cup (cup) • Milliliter to Cup
- Fluid ounce (fl oz) • Milliliter to Fluid ounce
- Cup (US) (cup) • Milliliter to Cup (US)
- Pint (US) (pt) • Milliliter to Pint (US)
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 volume measurements
Last verified: February 19, 2026