kg to Gallons Calculator — Kilograms to US / UK Gallons
Convert a mass in kilograms to US gallons, UK gallons, litres, and fluid ounces for common liquids including water, milk, gasoline, diesel and cooking oil. Pick a substance or enter a custom density.
kg
Substance
1 US gallon = 3.785 L • result = kg ÷ density ÷ 3.785
- 1
Volume in litres
10 ÷ 0.998 = 10.02Volume = mass ÷ density. - 2
Convert litres to US gallons
10.02 ÷ 3.7854 = 2.64701 US gallon = 3.785 411 784 L (exact).
How does this calculator work?
Divide mass (kg) by density (kg/L) to get litres, then divide by 3.785 for US gallons or 4.546 for UK gallons. For water (density ≈ 1 kg/L): 10 kg = 10 L = 2.642 US gal. For gasoline (0.737 kg/L): 10 kg = 13.57 L = 3.585 US gal.
Formula
How this is calculated
Volume and mass are related through density: V = m / ρ, where ρ is the substance's density in kg per litre. For water at 20 °C ρ ≈ 0.998 kg/L (effectively 1 for everyday purposes), so 1 kg of water ≈ 1 litre. Denser substances like honey (ρ ≈ 1.42 kg/L) give fewer litres per kilogram, while lighter liquids like gasoline (ρ ≈ 0.737 kg/L) give more.
Once the volume in litres is known, the calculator converts to gallons using the exact definitions: 1 US liquid gallon = 3.785 411 784 litres (defined under the international yard and pound agreement); 1 UK imperial gallon = 4.546 09 litres (defined by UK statute). The two gallon sizes differ by about 20 %, so always clarify which system is being used — US gallons dominate in North America, UK gallons in the UK and parts of the Commonwealth.
Densities here are typical values at approximately 20 °C and standard pressure. Temperature affects density — hot water is less dense than cold — so for precision work, use the density at your actual operating temperature. Select "Custom density" to enter the precise value for your substance.
Frequently asked questions
1 kg of water equals approximately 0.2642 US gallons (or 0.2200 UK gallons). Since water's density is ~1 kg/L, 1 kg ≈ 1 L, and 1 L = 0.2642 US gal.
Gasoline has a density of approximately 0.737 kg/L, so 1 kg ≈ 1.357 L ≈ 0.358 US gallons. Different fuel blends have slightly different densities (0.71–0.77 kg/L).
The US liquid gallon = 3.785 L and the UK imperial gallon = 4.546 L. The UK gallon is about 20% larger. Fuel efficiency (miles per gallon) figures differ significantly depending on which gallon is used.
TG we-Calculate Editorial Team. (2026). kg to Gallons Calculator — Kilograms to US / UK Gallons [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/kg-to-gallons-calculator
TG we-Calculate Editorial Team. "kg to Gallons Calculator — Kilograms to US / UK Gallons." TG we-Calculate. 2026. https://we-calculate.com/calculator/kg-to-gallons-calculator.
TG we-Calculate Editorial Team, "kg to Gallons Calculator — Kilograms to US / UK Gallons," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/kg-to-gallons-calculator
@misc{wecalculate_kg_to_gallons_calculator, title = {kg to Gallons Calculator — Kilograms to US / UK Gallons}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/kg-to-gallons-calculator}}, year = {2026}, note = {TG we-Calculate} }
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