Gallons to Liters
Convert US gallons to liters for fuel, cooking, and international comparison. 1 US gallon = 3.78541 L — enter any gallon value for instant metric conversion.
Enter your values above to see the results.
Tips & Notes
- ✓US gallon (3.785 L) vs. UK imperial gallon (4.546 L) — they are 20% different. A UK "4-star" petrol car tank of 55 liters = 55/4.546 = 12.1 UK gallons = 14.5 US gallons. Always verify which gallon when buying a vehicle overseas or comparing international specs.
- ✓Fuel economy conversion: mpg (US) × 0.4251 = L/100km (fuel consumption). mpg (US) × 1.20095 = mpg (UK). A 30 mpg US car uses 7.84 L/100km and gets 36.1 mpg UK.
- ✓Cooking at scale: US recipe using gallons converts to liters for commercial kitchen equipment. 1 gallon broth = 3.785 L; 5 gallons soup = 18.93 L; 10 gallons = 37.85 L. Most commercial kitchens use liter-calibrated pots and batch equipment.
- ✓Agricultural and industrial: US irrigation often specified in acre-feet or gallons per acre. 1 acre-inch of water = 27,154 gallons = 102,791 liters. A standard 5-gallon bucket = 18.93 L. 55-gallon drum = 208.2 L.
- ✓Pool volume: average residential pool (18,000 gallons) = 68,137 liters = 68.1 m³. Municipal water billing in the US uses thousands of gallons (CCF); internationally uses cubic meters. 1,000 gallons = 3,785 liters = 3.785 m³.
Common Mistakes
- ✗Using the UK gallon factor (4.546) for US gallon quantities — US recipes, US car fuel tanks, and US product labels use the US liquid gallon (3.785 L). The UK imperial gallon is 4.546 L — 20% larger. A US recipe calling for 1 gallon of milk needs 3.785 L, not 4.546 L.
- ✗Confusing US liquid gallon with US dry gallon — the US dry gallon (4.405 L) is used for dry commodities (grain, produce). The US liquid gallon (3.785 L) is used for fluids. They differ by 16%. US liquid gallon is far more common in everyday use.
- ✗Applying gallons to liters conversion to gallons per minute (flow rate) — GPM × 3.78541 = LPM (liters per minute). A 2 GPM shower head = 7.57 LPM. The unit conversion factor is the same for derived flow rate units, but the derived unit must be maintained.
- ✗Forgetting that fuel economy direction reverses between mpg and L/100km — higher mpg = better; lower L/100km = better. A car going from 30 to 40 mpg saves more fuel per mile than a car going from 10 to 20 mpg (despite equal mpg change), because fuel consumption is non-linear.
- ✗Converting recipe amounts without considering density — gallons and liters are volume units. Water: 1 US gallon = 3.785 kg. Milk (slightly denser): 1 US gallon ≈ 3.9 kg. Oil (less dense): 1 US gallon ≈ 3.4 kg. Always check whether a recipe means volume (gallons) or weight (pounds/kg) when ingredients have different densities.
Gallons to Liters Overview
The gallon is deeply embedded in American daily life — fuel stations quote price per gallon, pool chemicals are sold by gallon, and US recipes measure in cups and quarts. Converting to liters connects US volume measurements to the global metric standard used in manufacturing, international trade, and most of the world.
Gallons to liters formula:
L = US gal × 3.78541 | 1 US gal = 3.78541 L | 1 UK gal = 4.54609 L (20% larger)
EX: Car fuel tank 15 US gal → 15 × 3.78541 = 56.78 L. A 5-gallon water jug → 5 × 3.78541 = 18.93 L. 55-gallon drum → 55 × 3.78541 = 208.2 LInverse — liters to US gallons:
US gal = L / 3.78541 | US gal = L × 0.264172
EX: 40-liter fuel tank → 40/3.78541 = 10.57 US gallons. 1-liter water bottle → 1/3.78541 = 0.264 US gallonsCommon volume comparisons — gallons and liters:
| Volume | US Gallons | Liters | Context |
|---|---|---|---|
| Standard can of soda | 0.098 gal | 0.355 L | 12 fl oz can |
| 1-liter water bottle | 0.264 gal | 1.000 L | Standard bottle |
| 2-liter soda bottle | 0.528 gal | 2.000 L | Large bottle |
| 1 US gallon jug | 1.000 gal | 3.785 L | Milk jug reference |
| 5-gallon bucket | 5.000 gal | 18.93 L | Standard bucket |
| Car fuel tank (average) | 12-16 gal | 45.4-60.6 L | US passenger car |
| 55-gallon drum | 55.000 gal | 208.2 L | Standard industrial drum |
| Measure | US Liquid Gallon | UK Imperial Gallon | Difference |
|---|---|---|---|
| Liters | 3.78541 L | 4.54609 L | UK is 20.1% larger |
| Fluid ounces | 128 US fl oz | 160 UK fl oz | Different fl oz sizes too |
| Cubic inches | 231 in³ | 277.42 in³ | By definition |
| mpg at same consumption | 35 mpg (US) | 42.1 mpg (UK) | Same car, different mpg |
Frequently Asked Questions
One US liquid gallon = 3.78541 liters. Examples: 1 gal = 3.785 L; 2 gal = 7.571 L; 5 gal = 18.927 L; 10 gal = 37.854 L; 20 gal = 75.708 L; 50 gal = 189.271 L; 100 gal = 378.541 L. For the UK imperial gallon: 1 UK gal = 4.54609 L — 20.1% larger than the US gallon. Most international contexts use the US gallon when Americans mention gallons.
US liquid gallon: 231 cubic inches = 3.78541 liters = 128 US fluid ounces = 8 US pints. UK imperial gallon: 277.42 cubic inches = 4.54609 liters = 160 UK fluid ounces = 8 UK pints. The UK gallon is exactly 20.1% larger than the US gallon. This discrepancy means: a UK car with a "10-gallon tank" has 45.46 L (UK), while a US car with a "10-gallon tank" has 37.85 L (US). UK fuel efficiency in mpg (UK) is also 20% higher than US mpg for the same vehicle: a 40 mpg UK car = 33.3 mpg US.
L/100km = 235.214 / mpg (US). This is not a simple proportional conversion — it is an inverse relationship. Examples: 20 mpg = 11.76 L/100km; 25 mpg = 9.41 L/100km; 30 mpg = 7.84 L/100km; 35 mpg = 6.72 L/100km; 40 mpg = 5.88 L/100km; 50 mpg = 4.70 L/100km. Reverse: mpg = 235.214 / (L/100km). A European car rated 6.0 L/100km = 235.214/6 = 39.2 mpg (US). Note: the 235.214 constant = 100 km × 1,000 mL/L / (3.78541 L/gal × 1.60934 km/mile).
US volume unit relationships: 1 US gallon = 4 quarts = 8 pints = 16 cups = 128 fl oz = 3,785.41 mL = 3.78541 L. Metric relationships: 1 L = 1,000 mL = 0.2642 US gallons. Common references: 1-liter water bottle = 0.264 US gallons; 2-liter soda = 0.528 US gallons; 1 US gallon = 3.785 one-liter bottles. Intermediate units: 1 quart = 0.946 L; 1 pint = 0.473 L; 1 cup (US) = 236.6 mL; 1 fl oz (US) = 29.57 mL.
Liquid densities affect weight but not volume conversion (gallons to liters is pure volume): 1 US gallon = 3.78541 L regardless of liquid. But weights vary: 1 gallon of water = 3.785 L = 3.785 kg (at room temperature); 1 gallon of milk = 3.785 L ≈ 3.90 kg (slightly denser); 1 gallon of gasoline = 3.785 L ≈ 2.84 kg (less dense, ≈ 750 g/L); 1 gallon of honey = 3.785 L ≈ 5.16 kg (very dense, ≈ 1,360 g/L); 1 gallon of olive oil = 3.785 L ≈ 3.41 kg (≈ 900 g/L). For liquid transfer: always convert volume by gallons × 3.78541. For shipping weight: multiply by the specific liquid density.
US agricultural and industrial gallon uses: crop irrigation — water application rates in inches per acre or gallons per acre; 1 acre-inch of water = 27,154 gallons = 102,791 liters. Pesticide application: gallons per acre (GPA); a 20 GPA application on 500 acres = 10,000 gallons = 37,854 liters. Dairy: farm milk production reported in pounds and gallons; 1 gallon of milk ≈ 8.6 lbs ≈ 3.9 kg. Industrial: chemical drums are 55 gallons (208.2 L) — the standard unit for bulk chemicals. Swimming pools: residential 15,000-30,000 gallons = 56,781-113,562 liters. Monthly water utility billing: typical US household 5,000-10,000 gallons/month = 18,927-37,854 liters.