Liters to Gallons Calculator

About the Liters to Gallons Calculator

Litres are the standard unit for fuel, drinks, paint, engine oil, water tanks and aquariums in most of the world, but the United States sells petrol, milk and paint by the gallon, and older British figures use the imperial gallon. Converting litres to gallons helps compare fuel prices and tank sizes, understand an American car's figures, or follow instructions written for a different market.

This liters to gallons calculator converts litres to US gallons and UK (imperial) gallons exactly. It also shows US quarts, pints and fluid ounces, and if you enter a price per litre, it converts it to a price per gallon in both systems.

How to Use the Liters to Gallons Calculator

Enter the volume in litres.

Optionally, enter a price per litre — for example, the local fuel price — to see what it would be per US and UK gallon.

The gallons appear straight away, with the smaller US units and the price.

The Formula

  US gallons = litres ÷ 3.785411784
  UK gallons = litres ÷ 4.54609
  price per US gallon = price per litre × 3.785411784
  price per UK gallon = price per litre × 4.54609

Both gallons have exact definitions in litres. The US gallon is 231 cubic inches; the imperial gallon was defined in 1824 and is now fixed at exactly 4.54609 litres.

Step-by-Step Example

A 50-litre fuel tank.

  US gallons:  50 ÷ 3.785411784 = 13.2086 US gal
  UK gallons:  50 ÷ 4.54609 = 10.9985 UK gal

So a 50-litre tank holds about 13.2 US gallons or 11 UK gallons.

Fuel priced at 1.80 a litre costs 1.80 × 3.785411784 = 6.81 per US gallon, or 1.80 × 4.54609 = 8.18 per UK gallon, in the same currency.

Quick Reference

  1 L    = 0.264172 US gal = 0.219969 UK gal
  5 L    = 1.32086 US gal  = 1.09985 UK gal
  10 L   = 2.64172 US gal  = 2.19969 UK gal
  20 L   = 5.28344 US gal  = 4.39938 UK gal
  100 L  = 26.4172 US gal  = 21.9969 UK gal

A simple rule: there are about 3.8 litres in a US gallon and 4.5 in a UK gallon, so divide by 4 for a rough US figure and by 4.5 for a UK one.

Comparing Fuel Prices Across Countries

Fuel prices in Europe and most of Asia are quoted per litre, while the US quotes per gallon. Converting one to the other — and then converting the currency — shows how prices really compare. Because a gallon is nearly four litres, a US price per gallon looks about four times higher than a European price per litre even when fuel is cheaper. Converting to the same unit removes that illusion.

Smaller US Measures

A US gallon divides into 4 quarts, 8 pints or 128 US fluid ounces. So a litre is about 1.05669 US quarts, 2.11338 US pints or 33.814 US fluid ounces. These are useful for drinks, cooking and car fluids: a 5-litre can of engine oil is about 5.28 US quarts, the unit American oil capacities are usually given in.

Tanks, Aquariums and Water

Water tank, aquarium and pond sizes are often listed in litres in metric countries and in gallons in the US. A 200-litre aquarium is about 52.8 US gallons; a 1,000-litre water tank, a common size for rainwater, is about 264 US gallons or 220 UK gallons. Because a litre of water weighs about 1 kg, a 200-litre tank of water weighs about 200 kg, worth knowing before placing it on a shelf or floor.

Paint and Garden Products

Paint, varnish, fertiliser and weedkiller are sold in litres in most countries and in gallons or quarts in the US, and coverage rates follow the same units. A 2.5-litre tin of paint is about 0.66 US gallons, or a little over two and a half US quarts; a US gallon can of paint holds 3.79 litres. When a product's instructions give a dilution rate per gallon, convert the gallons to litres before mixing — and check whether the instructions mean US or imperial gallons, since older British garden products used the larger imperial gallon.

Engine Sizes and Fluid Capacities

Car specifications add another layer: engine size is quoted in litres even in the US, while oil and coolant capacities are often given in US quarts there. A car taking 4.5 litres of oil needs about 4.76 US quarts; a 60-litre fuel tank is about 15.85 US gallons. Converting the manufacturer's figure once, precisely, avoids overfilling or buying too little.

Understanding Your Result

The headline is the volume in US gallons.

The UK gallons line gives the imperial gallon figure.

The quarts, pints and ounces line gives smaller US units.

The price per gallon line converts a price per litre into prices per US and UK gallon.

When Should You Use This Calculator?

Use it to compare fuel prices and tank sizes between countries.

Use it for car fluids, paint and chemicals labelled in litres.

Use it for aquariums, ponds and water tanks.

Use it for recipes and drinks measured in litres when you think in US units.

Common Mistakes

Using the wrong gallon. A UK gallon is about 20 percent larger than a US gallon, so the answers differ noticeably.

Multiplying instead of dividing. From litres to gallons, divide.

Comparing per-litre and per-gallon prices directly. Convert first.

Forgetting quarts and pints differ too. US and UK quarts and pints are different sizes.

Rounding the factor to 4. It is about 5 percent out for US gallons, enough to mislead on a large fuel or water volume.

Ignoring the price currency. Convert the unit and the currency separately, using today's exchange rate for the currency step.