Gallons to Liters Converter
US gallons into liters — the ×3.785 direction, exactly.
Type in either field — the other updates instantly.
Gallons to Liters chart
| US gallons | Liters |
|---|---|
| 0.5 gal | 1.89 L |
| 1 gal | 3.79 L |
| 2 gal | 7.57 L |
| 5 gal | 18.93 L |
| 10 gal | 37.85 L |
| 13 gal | 49.21 L |
| 15 gal | 56.78 L |
| 20 gal | 75.71 L |
| 42 gal | 158.99 L |
| 55 gal | 208.2 L |
| 100 gal | 378.54 L |
| 1,000 gal | 3,785.41 L |
42 gal is the oil barrel (159 L); 55 gal the standard drum (208 L).
How this is calculated
liters = gal × 3.785411784 (exact — US gallon)
Reading American volumes in metric: the milk gallon is 3.79 L, a 15-gallon tank is 56.78 L, a 10,000-gallon pool is 37,854 L. Multiply by 3.785411784 — exact because the gallon is defined as 231 cubic inches and the inch as 25.4 mm.
Exactness chains from the inch: 231 in³ × (2.54 cm)³ = 3,785.411784 cm³ precisely. For UK imperial gallons multiply by 4.54609 instead — this page stays honestly US-only rather than blending the two.
Frequently asked questions
How many liters in 1 US gallon?
3.785 L (exactly 3.785411784). The UK imperial gallon is 4.546 L — always confirm which gallon a spec sheet means.
What does 30 mpg mean in metric?
30 US mpg = 12.75 km/L = 7.84 L/100km. Note the inversion: bigger mpg is better, smaller L/100km is better — crossing systems flips the intuition.
How many liters is a milk gallon?
3.79 L. The US half-gallon (1.89 L) and quart (0.95 L) scale down by clean halves — quart ≈ liter is the everyday approximation, 5.4% small.
How much does a gallon of water weigh?
About 3.785 kg (8.34 lb) at room temperature — a liter of water weighs a kilogram, so the volume number doubles as a mass estimate for water only.