Gallon Size Calculator
Enter an amount and pick its unit. The calculator converts it to litres, US and UK gallons, cubic feet and quarts, and gives the weight of that much water.
- US gallons
- UK gallons
- Litres
US recipes and fuel use US gallons. UK fuel economy figures use imperial gallons.
There are two common gallons, and they are not the same size. A US gallon is 3.785 litres. A UK or imperial gallon is 4.546 litres, about 20% more. So 10 US gallons are about 37.9 litres or 8.3 UK gallons, and weigh about 37.9 kg as water.
Gallon conversion chart
Common amounts. Search for an amount.
| US gallons | Litres | UK gallons |
|---|---|---|
| 1 | 3.79 | 0.83 |
| 2 | 7.57 | 1.67 |
| 5 | 18.93 | 4.16 |
| 10 | 37.85 | 8.33 |
| 20 | 75.71 | 16.65 |
| 50 | 189.27 | 41.63 |
| 55 | 208.2 | 45.8 |
| 100 | 378.54 | 83.27 |
Rounded to two places.
US gallons and litres
Liquid gallons. Slide the US gallons.
The jugs show how many US gallons, UK gallons and litres that is.
How to convert gallons
Any unit to any unit. Step through it.
Know which gallon
US or UK.
Dry gallons are for grain and produce, and are rarely used today.
US, UK or dry gallons
Gallon types. Compare them.
Liquid.
Imperial.
Dry goods.
An oil drum holds 55 US gallons, about 208 litres.
Before you convert
Unit checks. Tick each item.
Tick each item as you go.
Mpg in UK figures uses imperial gallons, so the numbers look about 20% better than US mpg.
What you get
Gallon conversion. Each tile explains one result.
Metric.
Gallons.
Gallons.
Volume.
Water.
A US gallon of water weighs about 8.34 lb, a UK gallon about 10 lb.
Frequently Asked Questions
No question matches that search.
How many litres are in a gallon?
Three point seven nine in a US gallon and four point five five in a UK gallon.
Is a UK gallon bigger than a US gallon?
Yes, by about twenty per cent.
How much does a gallon of water weigh?
About eight point three pounds for a US gallon and ten pounds for a UK gallon.
How many quarts are in a gallon?
Four, in both systems, though the quarts differ in size.
How many gallons are in a cubic foot?
About seven and a half US gallons.
Which gallon do recipes use?
US recipes use US gallons. Older UK recipes may use imperial.
What is a dry gallon?
A US unit for dry goods, about four point four litres.
The right gallon every time
Check which gallon you mean and convert in one step, whether for fuel, water or a recipe.
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