Volume Converter
Convert a volume into every metric, US liquid, Imperial and cubic unit at once. US and UK gallons are different units.
Volume units and definitions
The size of each unit is listed below. The US gallon (3.785411784 L) and the Imperial (UK) gallon (4.54609 L) are different units, and they are listed in separate groups. The Imperial gallon is about 20% larger.
| Unit | Size of one unit | Definition and source |
|---|---|---|
| Metric (SI) | ||
| m³ (cubic meter) | 1,000 L | 1 m³ = 1,000 L |
| L (liter) | 1 L | Exactly 1/1,000 of a cubic meter |
| dL (deciliter) | 0.1 L | Metric (SI) unit |
| mL (milliliter) | 0.001 L | 1 mL = 1 cm³ |
| US customary (liquid) | ||
| US gallon (US gal) | 3.785411784 L | 231 cubic inches. NIST Handbook 44 |
| US quart (US qt) | 0.946352946 L | 1/4 of a US gallon. NIST Handbook 44 |
| US pint (US pt) | 0.473176473 L | 1/8 of a US gallon. NIST Handbook 44 |
| US fluid ounce (US fl oz) | 0.0295735295625 L | 1/128 of a US gallon. NIST Handbook 44 |
| Imperial (UK) | ||
| Imperial gallon (UK gal) | 4.54609 L | Exactly 4.54609 L. A different unit from the US gallon (about 20% larger). NIST SP 811, NIST Handbook 44 |
| Cubic feet and cubic inches | ||
| cubic foot (ft³) | 28.316846592 L | The cube of a foot |
| cubic inch (in³) | 0.016387064 L | The cube of an inch |
The calculator converts your value to liters, then divides by the size of each unit. Calculations use exact fractions, and the only rounding is the one applied when a value is displayed.
Examples
- 1 US gallon = 3.785411784 L = 4 US quarts = 8 US pints = 128 US fluid ounces
- 1 Imperial gallon = 4.54609 L
- 1 L ≈ 0.264172 US gallons ≈ 0.219969 Imperial gallons
- 1 mL = 1 cm³
- 1 m³ = 1,000 L
Notes
- Only the US liquid measures are included here. US dry measures (such as the bushel) and cups or spoons for cooking are not included.
- The US gallon is 231 cubic inches. A UK or Canadian gallon is the Imperial gallon of exactly 4.54609 L.
- You can enter decimals (up to 12 digits before the decimal point and 6 decimal places). Use a period as the decimal separator.
Sources
The definitions on this page come from the sources below. Some values are the exact values this tool uses (for example, the pound as exactly 0.45359237 kg), and the sources may list them rounded; the notes in the table say which values are used by this tool.
- NIST Handbook 44, Appendix C: General tables of units of measurement (2026 edition)
- NIST Special Publication 811, Appendix B.8: Factors for units listed alphabetically
Frequently asked questions
How many liters are in a US gallon?
1 US gallon is 3.785411784 liters.
Is a US gallon the same as a UK gallon?
No. A US gallon is 3.785411784 L and an Imperial (UK) gallon is 4.54609 L. This tool lists them separately so they are not confused.
How do I convert liters to gallons?
Divide the liters by 3.785411784 for US gallons, or by 4.54609 for Imperial gallons. In this tool, just pick the units.