Complete comparison of metric and imperial volume measurement systems. Learn the differences, conversions, and when to use each system for accurate measurements.
Used by 95% of the world, including all scientific communities, most countries, and international trade.
Primarily used in the United States and to some extent in the UK, Canada, and other Commonwealth countries.
| System | Unit | Equivalent | Common Uses |
|---|---|---|---|
| Metric | Milliliter (mL) | 1 mL = 1 cm³ | Medicine, cooking, lab work |
| Metric | Liter (L) | 1 L = 1,000 mL | Beverages, fuel, containers |
| Metric | Cubic Meter (m³) | 1 m³ = 1,000 L | Construction, shipping, water |
| Metric | Cubic Centimeter (cm³) | 1 cm³ = 1 mL | Engineering, medicine |
| Imperial | Fluid Ounce (fl oz) | 1 fl oz = 29.574 mL | Cooking, beverages (US) |
| Imperial | Cup (c) | 1 c = 8 fl oz | Cooking, baking (US) |
| Imperial | Pint (pt) | 1 pt = 16 fl oz | Dairy, beer (US & UK) |
| Imperial | Quart (qt) | 1 qt = 32 fl oz | Milk, oil (US) |
| Imperial | Gallon (gal) | 1 gal = 128 fl oz | Fuel, large containers (US) |
| Imperial | Cubic Foot (ft³) | 1 ft³ = 28.317 L | Construction, shipping |
| Imperial | Cubic Inch (in³) | 1 in³ = 16.387 mL | Engineering, automotive |
The US and UK systems have different definitions for some volume units, which can cause significant conversion errors if not accounted for:
Difference: US and UK gallons differ by about 20%! A US gallon is 3.785 L, while a UK gallon is 4.546 L. Always specify which system you're using.
A US recipe calls for 2 cups of milk. What is that in milliliters?
2 cups × 236.588 mL/cup
= 473.2 mL
A car's fuel tank holds 50 L. How many US gallons is that?
50 L ÷ 3.785 L/gal
≈ 13.2 gal
A shipping container is 2.5 m³. What is that in cubic feet?
2.5 m³ × 35.315 ft³/m³
≈ 88.3 ft³
A UK gallon is 20% larger than a US gallon. Always specify which system you're using. Use our volume converter to avoid costly errors in international trade or shipping.
Common error: assuming 1 cup = 250 mL (metric cup) vs 236.6 mL (US cup). The difference may seem small but adds up in large batches.
Fluid ounces measure volume, not weight. 8 fl oz of water weighs about 8.3 oz, but 8 fl oz of oil weighs only about 7.2 oz. Use our cooking ingredient converter for accurate results.