Volume Conversion Calculator
Convert metric and cubic volume, explicitly labeled US liquid measures, and international acre-feet.
Content updated August 6, 2026
Teaspoon through gallon choices are US liquid units. Imperial, dry-volume, and product package units are different and are not silently substituted.
Convert one nonnegative volume across metric, cubic international-foot, U.S. liquid, and acre-foot units. The result table keeps equal metric units such as one millilitre and one cubic centimetre visible as separate labels.
All choices convert through cubic metres using exact defined relationships. U.S. liquid units are labeled because an unqualified gallon, pint, fluid ounce, or cup can mean a different quantity in another system.
The Volume Conversion formula
Converted volume = entered volume × cubic metres per source unit ÷ cubic metres per destination unitMetric, cubic international-foot, U.S. liquid, and international acre-foot factors use their stated exact definitions.
Worked example
One U.S. liquid gallon multiplied by exactly 0.003785411784 cubic metre per gallon and divided by 0.001 cubic metre per litre equals 3.785411784 litres.
Assumptions, rounding, and limitations
Assumptions
- The input is a nonnegative scalar volume.
- Cubic inch, foot, yard, and acre-foot use the international foot.
- Teaspoon through gallon are U.S. liquid measures derived from the 231-cubic-inch gallon.
- Litre and millilitre use exact SI-compatible definitions.
Rounding: The engine does not intentionally round intermediate results. Displays use up to 12 significant digits and scientific notation for very large or small values.
Limitations
- Does not include imperial liquid units, U.S. dry units, 240 mL nutrition-label cups, barrels, board feet, cooking package sizes, or historical survey-foot acre-feet.
- Does not infer mass, density, fill level, temperature expansion, irregular-container capacity, or recipe ingredient behavior.
Sources
- Handbook 133 (2026), Appendix E: General Tables of Units of Measurement — National Institute of Standards and Technology
- NIST Guide to the SI, Appendix B: Conversion Factors — National Institute of Standards and Technology
Cubic and capacity units can describe the same volume
One litre is exactly one cubic decimetre, and one millilitre is exactly one cubic centimetre. Cubic international-foot factors are the corresponding exact length factors cubed.
One international cubic foot is exactly 0.028316846592 cubic metre, while one cubic yard contains exactly 27 cubic feet.
US liquid labels prevent gallon and cup ambiguity
One U.S. liquid gallon is exactly 231 cubic inches, or 3.785411784 litres. The supported U.S. liquid quart, pint, cup, fluid ounce, tablespoon, and teaspoon are fixed divisions of that gallon.
Imperial liquid measures, U.S. dry measures, nutrition-label serving units, and product package sizes are different systems. They are not substituted for the U.S. liquid choices in this calculator.
Frequently asked questions
▶How many litres are in one US gallon?
One U.S. liquid gallon is exactly 3.785411784 litres.
▶How many millilitres are in one US cup?
One U.S. liquid cup in this calculator is exactly 236.5882365 millilitres, or one-sixteenth of a U.S. liquid gallon.
▶Is one millilitre equal to one cubic centimetre?
Yes. Both are exactly one-millionth of a cubic metre.
▶How many litres are in one cubic foot?
One international cubic foot is exactly 28.316846592 litres.
▶Does this use imperial gallons?
No. Gallon through teaspoon choices are explicitly U.S. liquid units. Imperial and U.S. dry measures require separate choices and are excluded.
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Open calculator →Disclaimer: Volume Conversion Calculator results are estimates for general information and education only, and are not financial, tax, legal or medical advice. Verify important decisions with a qualified professional.