How do I convert gallons to liters?

Multiply US gallons by 3.78541 to get liters. Formula: liters = gallons x 3.78541. Examples: 1 gal = 3.785 L, 5 gal = 18.927 L, 10 gal = 37.854 L, 20 gal = 75.708 L.

What is the difference between US gallons and UK gallons?

A US gallon = 3.78541 liters. A UK (Imperial) gallon = 4.54609 liters. The UK gallon is about 20% larger. Gas mileage figures are not directly comparable: a US MPG rating does not equal a UK MPG rating. Always specify which gallon when converting.

How many liters is a gas tank?

A typical compact car holds 40-50 liters (10.6-13.2 US gallons). Mid-size cars typically hold 55-65 liters (14.5-17.2 gal). Trucks and SUVs can hold 80-115 liters (21-30 gal). Electric vehicles use kWh (kilowatt-hours) instead of fuel volume.

How many liters is 5 gallons of water?

5 US gallons = 5 x 3.78541 = 18.927 liters. A standard 5-gallon water jug weighs about 18.9 kg (41.7 lbs). Water weighs approximately 1 kg per liter (1 liter = 1,000 grams = 2.205 lbs).

Gallons to Liters (gal to L) Converter

Also try: Liters to Gallons | mL to Cups

Gallons to Liters — Formula & Reference

The US liquid gallon equals exactly 3.785411784 liters. It is widely used in the United States for fuel, beverages, and other liquids. The Imperial (UK) gallon is slightly larger at 4.54609 L.

Formula (US gallon)

L = gal × 3.78541

Quick Reference

US Gallons	Liters	Context
0.264	1	1 liter
1	3.785	1 US gallon
5	18.93	5-gallon water jug
10	37.85	Small fuel tank
20	75.71	Standard car fuel tank

Related Converters

L → gal mL → Cups L → mL °C → °F KG → LBS

US vs Imperial Gallons

The US gallon equals exactly 3.785411784 litres. The imperial (UK) gallon equals 4.54609 litres — about 20% larger. Both descend from historical English gallons but diverged after American independence. To convert US gallons to litres, multiply by 3.785; for imperial gallons, multiply by 4.546. This distinction matters for fuel economy: 35 mpg (US) is equivalent to 35 × 1.20095 = 42 mpg (UK) for the same vehicle.

Gallons are used in the US for fuel, milk, and water (1 US gallon = 8 US pints = 128 US fl oz). The UK uses litres for fuel and drinks at retail, though recipes may still mention imperial measures. Canada uses litres for fuel but historically used imperial gallons. Industrial processes, swimming pools, and irrigation systems may specify capacity in US gallons; always confirm before ordering chemicals or planning infrastructure.

Gallons to Litres

US Gallons	Litres	Imperial Gallons	Litres
1	3.785	1	4.546
2	7.571	2	9.092
5	18.927	5	22.730
10	37.854	10	45.461
50	189.271	50	227.305

US and Imperial Gallons vs. the Metric Liter

Two gallon definitions exist: the US gallon (3.78541 liters) and the imperial gallon (4.54609 liters), about 20% larger. This distinction matters when comparing fuel prices internationally. A US fuel pump price per gallon yields much less fuel than the same number suggests per imperial gallon. The US gallon divides into 4 quarts, 8 pints, or 128 fluid ounces. Fluid sold in gallons at US grocery stores — milk, juice, paint — uses the US gallon exclusively. Converting US gallons to liters: multiply by 3.78541. Reverse: multiply liters by 0.264172. Aquariums and fish tanks in the US are sized in gallons, so a 10-gallon tank holds approximately 37.9 liters. International aquarium equipment specifications often use liters. Pool volume, water heater capacity, and irrigation quantities all require gallon-to-liter conversion when working across US and metric standards.

Gallons to Liters Reference Table

US Gallons	Liters	Context
0.5	1.89	Half gallon jug
1	3.785	Gallon of milk
5	18.93	Paint bucket
15	56.78	Small fuel tank
55	208.2	Drum barrel