Volume Converter

The volume converter can quickly convert one volume unit to another. It supports conversion between 25 common volume units, including metric units (cubic meters, cubic decimeters, liters, milliliters, etc.), imperial units (cubic miles, gallons, quarts, pints, fluid ounces), and Chinese traditional units (cubic zhang, cubic chi, cubic cun). Whether for liquid measurement, container capacity, or everyday volume conversion, this tool provides accurate results quickly. All calculations are done locally in your browser, protecting your privacy. Volume units depend heavily on context: liters and milliliters are common in daily use, cubic meters in engineering and logistics, and gallons, cups, or fluid ounces in regional recipes. Liquids, bulk materials, and gases may also be measured differently. The converter gives quick numerical results, but temperature, pressure, density, and rounding can matter in chemistry, shipping, construction, manufacturing, or medical dosing.

The SI base unit of volume is the cubic meter (m^3), with all derived units defined by exact integer or rational relationships. The litre was redefined at the 12th CGPM in 1964 as exactly 1 dm^3 = 10^-3 m^3, removing the older 1901-1964 definition (1 L = volume of 1 kg of pure water at 4 °C, which differed from 1 dm^3 by 28 ppm). Sub-multiples follow the SI prefix system: 1 mL = 1 cm^3 = 10^-6 m^3, 1 µL = 1 mm^3 = 10^-9 m^3. Cubic kilometres up to cubic micrometres span 27 orders of magnitude, which is why the converter normalizes every input to m^3 internally before scaling to the target unit, keeping multiplication chains within a single power-of-ten operation. US customary and Imperial liquid units share names but not values. NIST Handbook 44 fixes the US gallon at exactly 3.785411784 L (231 cubic inches by definition since 1893), the US fluid ounce at 1/128 US gal ≈ 29.5735 mL, and the US legal cup at 240 mL (FDA nutrition labeling) while the US customary cup is 8 US fl oz ≈ 236.5882 mL. The Imperial system (UK Weights and Measures Act 1985) sets the Imperial gallon at exactly 4.54609 L, with 1 Imp fl oz = 1/160 Imp gal ≈ 28.4131 mL. Note the gap goes both directions: the Imperial gallon is about 20 % larger than the US gallon, but the Imperial fluid ounce is about 4 % smaller than the US fluid ounce because the two systems divide their gallons differently (128 vs 160). The metric cup standardized in Australia, New Zealand, and Latin America is exactly 250 mL. Industry units include the oil barrel (1 bbl = 42 US gal ≈ 158.987 L, set by the Pennsylvania petroleum industry in 1872) and the US beer barrel (31 US gal). Chinese market units defined in GB 3102.3-1993 align 1 升 (shēng) = 1 L exactly, 1 立方尺 = 0.037037 m^3 (1/27 m^3 since 1 市尺 = 1/3 m), and the corresponding 立方寸 = 0.000037 m^3. Floating-point precision matters when chaining conversions: IEEE 754 double precision provides about 15-17 significant decimal digits, so successive multiplications by long factors like 3.785411784 accumulate rounding error in the last ULP, which the tool mitigates by storing each factor as a canonical decimal string and applying it in a single multiplication rather than a chain.

• SI base: 1 m^3 = 10^3 dm^3 = 10^3 L = 10^6 cm^3 = 10^6 mL = 10^9 mm^3 = 10^9 µL (CGPM 1964 redefinition of the litre)
• US gallon (NIST Handbook 44): exactly 3.785411784 L = 231 in^3; 1 US fl oz = 1/128 gal ≈ 29.5735 mL; 1 US legal cup (FDA) = 240 mL, 1 US customary cup ≈ 236.5882 mL
• Imperial gallon (UK Weights and Measures Act 1985): exactly 4.54609 L; 1 Imp fl oz = 1/160 Imp gal ≈ 28.4131 mL; Imp gal is ~20 % larger but Imp fl oz is ~4 % smaller than US
• Cubic-length units: 1 ft^3 = (0.3048)^3 m^3 ≈ 28.3168 L, 1 in^3 = (0.0254)^3 m^3 ≈ 16.3871 mL, 1 yd^3 ≈ 764.555 L (exact from NIST length definitions)
• Industry units: oil barrel = 42 US gal = 158.987294928 L (Pennsylvania 1872 convention); US beer barrel = 31 US gal ≈ 117.348 L; do not confuse the two when reading petroleum vs brewery reports
• Chinese GB 3102.3-1993: 1 升 = 1 L exactly; 1 市尺 = 1/3 m, so 立方尺 = 1/27 m^3 ≈ 37.037 L; 立方寸 = 立方尺 / 1000 ≈ 37.037 mL
• Precision: IEEE 754 double gives 15-17 significant decimals; the converter applies a single multiplication by the canonical factor (e.g., 3.785411784) rather than chaining to keep last-ULP error below 1 part in 10^15