Specific Volume Converter
Convert specific volume, the volume taken up by a unit of mass, between cubic meters per kilogram, cubic centimeters per gram, liters per kilogram, cubic feet per pound and more. Pick two units, enter a value and read the result instantly.
Select two units to see the conversion factor.
This tool converts specific volume (volume per mass) only. It is not density (mass per volume), which is its reciprocal. Do not enter a density here, and do not read a result as a density.
Specific Volume Formula
Specific volume is volume divided by mass: v = V ÷ m. Every unit is a fixed multiple of the cubic meter per kilogram. Result = value × (source factor ÷ target factor). The building blocks are exact: 1 L = 0.001 m³, 1 cm³ = 10⁻⁶ m³, 1 g = 0.001 kg, 1 ft = 0.3048 m, 1 lb = 0.45359237 kg, 1 US gallon = 3.785411784 L and 1 UK gallon = 4.54609 L.
What Is Specific Volume?
Specific volume is the volume that one unit of mass occupies, v = V ÷ m. The SI unit is the cubic meter per kilogram (m³/kg). It is the standard way to describe how “spread out” a fluid is in thermodynamics: a gas has a large specific volume and a liquid or solid a small one. Water is close to 0.001 m³/kg (1 cm³/g or 1 L/kg), dry air at room temperature about 0.83 m³/kg, and saturated steam at 100 °C about 1.67 m³/kg.
Specific volume depends on temperature and pressure, and it changes sharply when a substance boils or condenses, which is why steam tables list it for both the liquid and the vapour. Metric work uses m³/kg, cm³/g, L/kg and L/g. US customary and HVAC work uses ft³/lb and ft³/kg, and the list also includes gallons per pound, where the US and UK gallons are different sizes.
Do not confuse specific volume with density. Specific volume is volume per mass. Density is mass per volume. They are reciprocals, v = 1 ÷ ρ, so they are different quantities with different units, and a unit of one cannot be converted into a unit of the other by a fixed factor. This tool also does not convert molar volume (volume per mole) or volumetric flow (volume per time).
Supported Units
This converter supports the following 8 specific volume units. The last column gives the value of each unit in the base unit, the cubic meter per kilogram. “Pound” here is the pound of mass (0.45359237 kg).
| Unit | Symbol | Value in m³/kg |
|---|---|---|
| Cubic meter per kilogram | m³/kg | 1 |
| Cubic centimeter per gram | cm³/g | 0.001 |
| Liter per kilogram | L/kg | 0.001 |
| Liter per gram | L/g | 1 |
| Cubic foot per kilogram | ft³/kg | 0.02831684659 |
| Cubic foot per pound | ft³/lb | 0.06242796058 |
| Gallon (US) per pound | gal (US)/lb | 0.008345404452 |
| Gallon (UK) per pound | gal (UK)/lb | 0.01002241285 |
How to Use the Specific Volume Converter
- Type the specific volume in the value box. Decimals and scientific notation such as 0.0025 or 2.5e-3 are accepted.
- Choose the From unit and the To unit.
- The result appears instantly, or press Convert Now. Very large or very small results are shown in scientific notation.
- Use Swap Units to reverse the conversion, Copy Result to copy the answer, open Show this value in all units for a full list, and Clear to start again.
Step-by-step by hand
- Find the size of each unit in the common base unit (m³/kg): 1 cm³/g = 0.001 m³/kg and 1 ft³/lb = 0.06242796058 m³/kg.
- Divide the source size by the target size to get the conversion factor: 0.001 ÷ 0.06242796058 = 0.01601846337, so 1 cm³/g = 0.01601846337 ft³/lb.
- Multiply by your value: 1 cm³/g × 0.01601846337 = 0.01601846337 ft³/lb.
Specific volume cannot be negative, so only zero and positive values are accepted.
Common Specific Volume Conversions
- Water: 1 cm³/g equals 0.001 m³/kg, 1 L/kg and 0.01601846337 ft³/lb.
- Dry air near room temperature: 0.83 m³/kg equals 13.2953246 ft³/lb.
- Saturated steam at 100 °C: 1.672 m³/kg equals 26.78287076 ft³/lb.
- Imperial to metric: 13.3 ft³/lb equals 0.8302918757 m³/kg.
- Liters per kilogram: 850 L/kg equals 0.85 m³/kg.
- Gallons per pound: 0.12 gal (US)/lb equals 1.001448534 L/kg, and the same figure in UK gallons per pound is a different value, 1.202689543 L/kg.
Cubic Centimeter per Gram to Other Specific Volume Units
Quick reference for frequently used values
| cm³/g | m³/kg | L/kg | ft³/lb |
|---|---|---|---|
| 0.1 | 0.0001 | 0.1 | 0.001601846337 |
| 0.5 | 0.0005 | 0.5 | 0.008009231687 |
| 1 | 0.001 | 1 | 0.01601846337 |
| 5 | 0.005 | 5 | 0.08009231687 |
| 10 | 0.01 | 10 | 0.1601846337 |
| 100 | 0.1 | 100 | 1.601846337 |
| 830 | 0.83 | 830 | 13.2953246 |
| 1,672 | 1.672 | 1,672 | 26.78287076 |
Where and Why This Conversion Is Used
- Thermodynamics: steam and refrigerant tables, phase-change calculations and cycle analysis.
- HVAC and air handling: air volume per unit mass in ft³/lb when sizing fans and ducts.
- Compressors, turbines and boilers: volume flow from mass flow using v.
- Chemical engineering and storage: how much tank volume a given mass of fluid or powder needs.
- Materials and packaging: bulk volume of powders, foams and granular products per unit mass.
Limitations
- The converter changes units only. The specific volume of a real substance depends on temperature, pressure and phase, so use a value for your conditions.
- To go between specific volume and density you take a reciprocal, which is a separate calculation from a unit conversion.
Important Differences Between Related Measurements
- Specific volume vs density: specific volume is volume per mass (m³/kg). Density is mass per volume (kg/m³). They are reciprocals: 0.001 m³/kg corresponds to 1,000 kg/m³. A unit conversion never turns one into the other.
- Specific volume vs volume: volume (m³) is the space an object occupies. Specific volume is that space per unit of mass, so it is a property of the material at given conditions, not of how much of it you have.
- Specific volume vs molar volume: molar volume is volume per mole (m³/mol). Specific volume is volume per mass. They differ by the molar mass.
- Specific volume vs specific gravity: specific gravity is a unit-free ratio of densities. Specific volume carries units of volume per mass.
Each converter on this site changes units within one quantity only, and none of them mixes quantities. The related tools are: Velocity - Angular, Acceleration, Acceleration - Angular, Density, Specific Volume, Moment of Inertia, Moment of Force and Torque.