Volume Converter
Convert liters, milliliters and cubic meters to US and imperial gallons, pints, cups and fluid ounces — including the difference between a US pint and an imperial pint. Results update as you type; exact factors shown.
One US gallon is 3.7854 liters — see the exact factor, not a rounded rule of thumb.
How the volume converter works
Volumes convert through the liter (exactly 1 dm³). The US gallon is exactly 3.785411784 L (231 cubic inches); the imperial gallon is exactly 4.54609 L. A US fluid ounce is 29.5735 mL, an imperial fluid ounce 28.4131 mL; a US pint is 16 US fl oz, an imperial pint 20 imperial fl oz.
The US uses customary units (US gallon, short ton, °F) in daily life; NIST SP 811 gives the exact SI factors.
Common volume conversions
| From | To | Units |
|---|---|---|
| 1 L | 0.2642 US gal | liter to US gallons |
| 1 US gal | 3.7854 L | US gallon to liters |
| 1 imp gal | 4.5461 L | imperial gallon to liters |
| 1 imp pt | 568.2613 mL | imperial pint to milliliters |
| 1 US pt | 473.1765 mL | US pint to milliliters |
| 1 US cup | 236.5882 mL | US cup to milliliters |
| 1 US fl oz | 29.5735 mL | US fluid ounce to milliliters |
| 1 m³ | 1,000 L | cubic meter to liters |
| 1 ft³ | 28.3168 L | cubic foot to liters |
| 1 L | 1,000 mL | liter to milliliters |
Units in this converter and their exact factors
| Unit | Symbol | One unit in liters |
|---|---|---|
| milliliter | mL | 0.001 liter |
| liter | L | 1 liter |
| cubic meter | m³ | 1,000 liter |
| teaspoon (metric) | tsp | 0.005 liter |
| tablespoon (metric) | tbsp | 0.015 liter |
| cup (metric) | cup | 0.25 liter |
| US fluid ounce | US fl oz | 0.0295735296 liter |
| US cup | US cup | 0.2365882365 liter |
| US pint | US pt | 0.473176473 liter |
| US gallon | US gal | 3.785411784 liter |
| imperial fluid ounce | imp fl oz | 0.0284130625 liter |
| imperial pint | imp pt | 0.56826125 liter |
| imperial gallon | imp gal | 4.54609 liter |
| cubic foot | ft³ | 28.316846592 liter |
FAQFrequently asked questions about volume conversion
Why are US and imperial gallons different?
The US kept the old English wine gallon (231 cubic inches, 3.785 L) after independence; the UK redefined its gallon in 1824 as the volume of 10 pounds of water (4.546 L). The imperial gallon is about 20% larger.
How many milliliters are in a cup?
A metric cup is 250 mL; a US customary cup is 236.6 mL; a US "legal" cup on nutrition labels is 240 mL.
How many liters are in a cubic meter?
Exactly 1,000 liters.
Is a UK pint bigger than a US pint?
Yes — an imperial pint is 568 mL, a US pint 473 mL.
How many liters in a US gallon?
Exactly 3.785411784 L. The imperial gallon is 4.54609 L.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Institute of Standards and Technology (NIST) — United States's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.