Water Density Calculator
Calculate water density, specific weight, specific gravity, and thermal expansion coefficient based on temperature and pressure conditions.
Environmental Conditions
Enter temperature and pressure conditions
Standard conditions: 20°C (68°F)
Atmospheric pressure: 101.325 kPa (1 atm)
Water Properties
Calculated water properties at specified conditions
Density (ρ)
0.000 kg/m³
0.000000 g/cm³
Specific Weight (γ)
0.000 kN/m³
0.0 N/m³
Specific Gravity (SG)
0.000000
Relative to water at 4°C
Thermal Expansion Coefficient
0.00 × 10⁻⁶ /°C
Volume change per degree Celsius
Formulas and Relationships
Mathematical relationships used in calculations
Specific Weight
γ = ρ × g
Where g = 9.81 m/s² (gravitational acceleration)
Specific Gravity
SG = ρ / ρ₄°C
Where ρ₄°C = 999.972 kg/m³ (water density at 4°C)
Density vs Temperature
ρ(T) = 999.83952 + 16.945176T - 7.9870401×10⁻³T² - 46.170461×10⁻⁶T³ + 105.56302×10⁻⁹T⁴ - 280.54253×10⁻¹²T⁵
Empirical formula for pure water (T in °C)
Engineering Applications
Common uses in civil engineering
Hydraulic Engineering
- • Flow calculations in pipes and channels
- • Pressure calculations in water systems
- • Buoyancy force calculations
Structural Engineering
- • Hydrostatic pressure on retaining walls
- • Water loading on structures
- • Foundation design in saturated soils
Environmental Engineering
- • Water treatment plant design
- • Thermal expansion in pipelines
- • Density stratification in reservoirs
Note: These calculations are for pure water. Real water may contain dissolved substances that affect density. For seawater, add approximately 2.5% to the density.