Multiply gallons by 3.785 to get litres, then by the density in kg/L. A U.S. gallon of diesel weighs about 3.18 kg.
How to use the Gallons to kg Converter
- Substance
- Custom density
- US gallons
- Every result field is editable: type into Kilograms or any other result and US gallons plus every other field update to match.
Results update as you type, and every field accepts the units shown in its menu.
How it works
The calculator converts your volume to SI units, looks up the density of the selected substance in kg/m³ and multiplies. The result is then shown in kilograms and other common units. Every result field is editable, so you can work backwards too.
How to convert US gallons to kilograms
- Find the density of the substance (the menu fills it in for you).
- Convert the volume to SI units if needed.
- Multiply volume by density to get mass.
- Convert the answer to kilograms.
1 US gallon of common substances in kilograms
| Substance | Kilograms per 1 US gal |
|---|---|
| Water (4 °C) | 3.7854118 |
| Water (20 °C) | 3.778598 |
| Water (100 °C) | 3.6279387 |
| Seawater | 3.8800471 |
| Milk | 3.8989741 |
| Gasoline (petrol) | 2.8201318 |
| Diesel | 3.1797459 |
| Jet fuel (Jet A) | 3.0434711 |
| Kerosene | 3.0661835 |
| Crude oil (typical) | 3.2933083 |
| Ethanol | 2.9866899 |
| Propane (liquid) | 1.866208 |
| Olive oil | 3.456081 |
| Vegetable oil | 3.4863643 |
| Honey | 5.3752847 |
| Beer | 3.8232659 |
| Orange juice | 3.9557553 |
| Latex paint (typical) | 4.9210353 |
Densities used
| Substance | kg/m³ | g/mL | lb/US gal |
|---|---|---|---|
| Water (4 °C) | 1,000 | 1 | 8.3454045 |
| Water (20 °C) | 998.2 | 0.9982 | 8.3303827 |
| Water (100 °C) | 958.4 | 0.9584 | 7.9982356 |
| Seawater | 1,025 | 1.025 | 8.5540396 |
| Milk | 1,030 | 1.03 | 8.5957666 |
| Gasoline (petrol) | 745 | 0.745 | 6.2173263 |
| Diesel | 840 | 0.84 | 7.0101397 |
| Jet fuel (Jet A) | 804 | 0.804 | 6.7097052 |
| Kerosene | 810 | 0.81 | 6.7597776 |
| Crude oil (typical) | 870 | 0.87 | 7.2605019 |
| Ethanol | 789 | 0.789 | 6.5845241 |
| Propane (liquid) | 493 | 0.493 | 4.1142844 |
| Olive oil | 913 | 0.913 | 7.6193543 |
| Vegetable oil | 921 | 0.921 | 7.6861175 |
| Honey | 1,420 | 1.42 | 11.850474 |
| Beer | 1,010 | 1.01 | 8.4288585 |
| Orange juice | 1,045 | 1.045 | 8.7209477 |
| Latex paint (typical) | 1,300 | 1.3 | 10.849026 |
Inputs explained
| Field | What to enter |
|---|---|
| Substance | Choose one: Water (4 °C), Water (20 °C), Water (100 °C), Seawater … |
| Custom density | Units: g/cm³, kg/m³, kg/L, lb/ft³, lb/US gal |
| US gallons | Units: US gal, L, mL, cL, dL, m³ … |
What each result means
- Kilograms = [US gallons] × [Density used]
- Pounds = [US gallons] × [Density used]
- Grams = [US gallons] × [Density used]
Formula
mass = volume × densityWorked example
Inputs — Substance: Diesel; Custom density: 1 g/cm³; US gallons: 1 US gal.
Results — Density used = 0.84 g/cm³; Kilograms = 3.179746 kg; Pounds = 7.01014 lb; Grams = 3,179.745899 g.
Frequently asked questions
How many kg is a gallon of water?
About 3.78 kg.
How many kg is a gallon of diesel?
About 3.18 kg.
Why does the answer change with the ingredient?
US gallons and kilograms measure different things (volume and weight), so the conversion depends on how dense the material is.
What if my ingredient is not listed?
Choose “Custom density” and type its density; the label or a quick weigh-and-measure test will give it.
What formula does the Gallons to kg Converter use?
mass = volume × density.