Gallon to Kg Converter (gallons of water to kilograms)
A gallon is a volume, so its weight depends on the liquid and on which gallon you mean. A US gallon of water weighs 3.785 kg (8.34 lb) and an imperial (UK) gallon of water weighs 4.546 kg (10.02 lb). Pick the liquid above, switch between US and UK gallons, or change the weight unit to pounds to see the answer in the form you need.
3.7854118 kilograms of water = 1 us gallon (density 1 kg/L). Volume = mass ÷ density, mass = volume × density.
How to convert gallons to kg
Kilograms = gallons × liters per gallon × density (kg/L)
A US gallon is 3.785411784 liters and a UK gallon is 4.54609 liters. Multiply by the density of the liquid: water is 1 kg/L, so a US gallon of water is 3.785 kg. For pounds, multiply kilograms by 2.2046, which gives the familiar 8.34 lb per US gallon of water.
Weight of 1 US gallon by liquid
| Substance | Density (kg/L) | 1 us gallon weighs |
|---|---|---|
| Water | 1 | 3.7854118 kg |
| Milk | 1.03 | 3.8989741 kg |
| Seawater | 1.025 | 3.8800471 kg |
| Petrol / gasoline | 0.74 | 2.8012047 kg |
| Diesel | 0.83 | 3.1418918 kg |
| Cooking oil | 0.92 | 3.4825788 kg |
| Honey | 1.42 | 5.3752847 kg |
| Ethanol / alcohol | 0.789 | 2.9866899 kg |
| Wheat flour | 0.593 | 2.2447492 kg |
| Sugar (granulated) | 0.85 | 3.2176 kg |
| Rice | 0.75 | 2.8390588 kg |
| Sand (dry) | 1.6 | 6.0566589 kg |
| Concrete | 2.4 | 9.0849883 kg |
| Ice | 0.917 | 3.4712226 kg |
| Paint | 1.3 | 4.9210353 kg |
| LPG (liquid) | 0.55 | 2.0819765 kg |
US gallons to kg of water
| US gallons | Kilograms of water |
|---|---|
| 1 gal (US) | 3.7854118 kg |
| 2 gal (US) | 7.5708236 kg |
| 3 gal (US) | 11.356235 kg |
| 4 gal (US) | 15.141647 kg |
| 5 gal (US) | 18.927059 kg |
| 6 gal (US) | 22.712471 kg |
| 8 gal (US) | 30.283294 kg |
| 10 gal (US) | 37.854118 kg |
| 15 gal (US) | 56.781177 kg |
| 20 gal (US) | 75.708236 kg |
| 25 gal (US) | 94.635295 kg |
| 30 gal (US) | 113.56235 kg |
| 40 gal (US) | 151.41647 kg |
| 50 gal (US) | 189.27059 kg |
| 55 gal (US) | 208.19765 kg |
| 100 gal (US) | 378.54118 kg |
| 500 gal (US) | 1,892.7059 kg |
| 1,000 gal (US) | 3,785.4118 kg |
Gallons of water, milk and fuel
A gallon of milk weighs about 3.9 kg (8.6 lb), slightly more than water. A gallon of petrol weighs about 2.8 kg (6.2 lb), which is why a full tank is lighter than the same volume of water. A 5-gallon water jug is 18.9 kg (41.7 lb), and a 55-gallon drum of water is 208 kg (459 lb). In the UK, the imperial gallon makes every figure 20% larger: a UK gallon of water is 4.546 kg or 10.02 lb, a fact often taught as "a pint of pure water weighs a pound and a quarter".
For liters instead of gallons, use the gallon to liter converter, and for weight to volume the kg to liter converter.
Frequently asked questions
How much does a gallon of water weigh?
A US gallon of water weighs 3.785 kg or 8.34 lb at room temperature. A UK (imperial) gallon weighs 4.546 kg or 10.02 lb.
How many kg is 1 gallon?
For water, 3.785 kg (US gallon) or 4.546 kg (UK gallon). For other liquids multiply those figures by the liquid's density: petrol is about 0.74, so a US gallon of petrol is 2.8 kg.
How much does a gallon of milk weigh?
About 3.9 kg (8.6 lb) for a US gallon, because milk's density is about 1.03 kg/L.
Does temperature change the weight of a gallon?
Slightly. Water is densest at 4 °C and about 0.4% lighter per gallon at 40 °C. For household purposes the difference does not matter.
Related calculators
Last updated . Formulas are shown on the page and checked against the worked example.
Densities are typical room-temperature values and vary with temperature, composition and packing. Water is taken as 1 kg/L. Results are rounded to 8 significant digits.