Specific Volume Converter
Convert specific volume between m³/kg, cm³/g, L/kg, ft³/lb, and other specific volume units with scientific precision.
⚠️ Important: Specific volume varies significantly with temperature and pressure. This tool provides technical conversions only. Always consult thermodynamic tables and material datasheets for property values at your operating conditions.
Specific Volume Units Explained
Cubic Meter/Kilogram (m³/kg)
The SI unit of specific volume. It represents the volume occupied by one kilogram of a substance. v = V / m.
Common uses: Thermodynamic tables, steam tables, gas properties, international standards.
Cubic Centimeter/Gram (cm³/g)
Specific volume in CGS units. 1 cm³/g = 0.001 m³/kg. Commonly used in chemistry and material science.
Note: Water has a specific volume of approximately 1 cm³/g at 4°C.
Liter/Kilogram (L/kg)
Specific volume using liters and kilograms. 1 L/kg = 0.001 m³/kg. Used in engineering calculations.
Common uses: Fluid properties, HVAC calculations, material density conversions.
Cubic Foot/Pound (ft³/lb)
Specific volume in US customary units. 1 ft³/lb ≈ 0.0624 m³/kg. Common in US engineering.
Common uses: US HVAC design, steam tables in US format, American engineering standards.
Specific Volume Definition
Specific volume is the inverse of density and represents volume per unit mass: v = V / m = 1 / ρ
- v: Specific volume (m³/kg)
- V: Total volume (m³)
- m: Mass (kilogram)
- ρ: Density (kg/m³)
Relationship to Density
Specific volume and density are reciprocal properties:
- Specific volume = 1 / Density
- Example: Water with density 1000 kg/m³ has specific volume 0.001 m³/kg or 1 L/kg
- Air at STP: density 1.20 kg/m³, specific volume 0.833 m³/kg
- Steam (100°C, 1 atm): density 0.598 kg/m³, specific volume 1.673 m³/kg
Applications in Thermodynamics
Specific volume is critical in thermodynamic calculations:
- Steam tables: Used with temperature and pressure to find other properties
- Ideal gas law:
P × v = R × T (specific form)
- Compressibility: Measures how volume changes with pressure
- Quality factor: For two-phase mixtures (liquid + vapor)
- Enthalpy calculations:
h = u + P × v
Temperature and Pressure Dependence
Specific volume varies significantly with conditions:
- Liquids: Relatively incompressible, small changes with pressure and temperature
- Gases: Highly compressible, large changes with pressure and temperature
- Two-phase region: Specific volume increases dramatically during phase change
- Temperature effect: Heating usually increases specific volume (expansion)
- Pressure effect: Increasing pressure usually decreases specific volume (compression)
Important: Always reference temperature and pressure when using specific volume data.
Typical Specific Volume Values (at 20°C, 1 atm)
- Water (liquid): 0.001 m³/kg = 1 L/kg = 1 cm³/g
- Ice: 0.00109 m³/kg (expands when freezing)
- Air: 0.833 m³/kg
- Aluminum (solid): 0.00037 m³/kg
- Iron (solid): 0.000128 m³/kg
- Mercury (liquid): 0.0000735 m³/kg
- Water vapor (100°C, 1 atm): 1.673 m³/kg
Common Applications
Specific volume is essential in:
- HVAC Systems: Air and refrigerant properties, duct sizing
- Power Generation: Steam turbine design, throttling calculations
- Chemical Engineering: Process design, pipe sizing, fluid flow
- Materials Science: Density determination, purity analysis
- Thermodynamic Cycles: Rankine, Brayton, Otto cycle analysis
- Compressor Design: Volume flow calculations, compression ratio
- Refrigeration Systems: Saturation properties, superheating
Quality Factor in Two-Phase Regions
For mixtures of liquid and vapor:
- Quality (x): Mass fraction of vapor = m_vapor / m_total (0 ≤ x ≤ 1)
- Specific volume:
v = v_f + x×v_fg where v_fg = v_g - v_f
- Two-phase region: Specific volume increases dramatically from liquid to vapor
- Critical point: Liquid and vapor specific volumes become equal