Water Density, Specific Weight and Thermal Expansion Coefficients

Calculate water density, specific weight, and thermal expansion coefficients based on temperature and pressure. Pure water reaches maximum density of 1000 kg/m³ at 4°C. This calculator provides density values in multiple units (g/cm³, kg/m³, lb/ft³, lb/gal, sl/ft³) across temperature ranges 0-370°C and pressure conditions from atmospheric to 10,000 psi.

Calculator

Inputs

Results

Density-- g/cm³
Density-- kg/m³
Density-- lb/ft³
Density-- lb/gal(US liq)
Density-- sl/ft³
Specific Weight-- kg/(m² s²)
Specific Weight-- kN/m³
Specific Weight-- lbf/ft³
Temperature (°C)Density (g/cm³)Density (kg/m³)Specific Weight (kN/m³)Thermal Expansion (*10⁻⁴K⁻¹)
0.10.9998495999.859.8052-0.68
40.9999749999.979.80640.003
100.9997999.79.80370.88
200.9982067998.219.78912.07
250.997047997.059.77772.57
300.9956488995.659.7643.03
400.9922152992.229.73033.84
500.98804988.049.68944.54
600.9832983.29.64195.16
700.97776977.769.58865.71
800.97179971.799.536.21
900.96531965.319.46656.66
1000.95835958.359.39827.03

Key Formulas

Density Formula:

  • ρ = m / V
    • ρ = density
    • m = mass
    • V = volume

Specific Weight Formula:

  • γ = (m × g) / V = ρ × g
    • γ = specific weight
    • g = acceleration due to gravity (9.807 m/s² or 32.174 ft/s²)
    • ρ = density

Example 1: Specific Weight of Water at 4°C (SI System)

  • γ = 1000 kg/m³ × 9.807 m/s² = 9,807 N/m³ = 9.807 kN/m³

Example 2: Specific Weight of Water at 39°F (Imperial System)

  • γ = 1.940 sl/ft³ × 32.174 ft/s² = 62.4 lbf/ft³

Important Notes:

  • Maximum water density: 1000 kg/m³ at 4°C (39.2°F)
  • Temperature range for calculations: 0-370°C or 32-700°F
  • Valid pressure ranges: 0-100°C at 1 atm, >100°C at saturation pressure
  • Thermal expansion is non-linear with temperature