Water Properties vs Temperature
Density, viscosity, specific heat, conductivity and vapor pressure of liquid water from 0 to 100 C.
Almost every flow, pump and heat transfer calculation for water needs a few properties, and they all change with temperature. This table gives the ones engineers use most, every 10 degrees from freezing to boiling, at atmospheric pressure.
The table
| Temperature (C) | Density (kg/m3) | Dynamic viscosity (mPa s) | Kinematic viscosity (mm2/s) | Specific heat (J/kg K) | Thermal conductivity (W/m K) | Vapor pressure (kPa) |
|---|---|---|---|---|---|---|
| 0 | 999.8 | 1.792 | 1.7924 | 4217 | 0.561 | 0.611 |
| 10 | 999.7 | 1.307 | 1.3074 | 4193 | 0.58 | 1.228 |
| 20 | 998.2 | 1.002 | 1.0038 | 4182 | 0.598 | 2.339 |
| 30 | 995.7 | 0.797 | 0.8004 | 4179 | 0.615 | 4.246 |
| 40 | 992.2 | 0.653 | 0.6581 | 4179 | 0.631 | 7.383 |
| 50 | 988 | 0.547 | 0.5536 | 4181 | 0.643 | 12.35 |
| 60 | 983.2 | 0.467 | 0.475 | 4185 | 0.654 | 19.944 |
| 70 | 977.8 | 0.404 | 0.4132 | 4190 | 0.663 | 31.198 |
| 80 | 971.8 | 0.355 | 0.3653 | 4197 | 0.67 | 47.412 |
| 90 | 965.3 | 0.315 | 0.3263 | 4205 | 0.675 | 70.18 |
| 100 | 958.4 | 0.282 | 0.2942 | 4216 | 0.679 | 101.419 |
Source and notes: Liquid water near atmospheric pressure, typical handbook values (CRC Handbook, IAPWS). Vapor pressure from the Hyland-Wexler equation.
How to use this table
- Find the water temperature in the first column.
- Take the density for mass flow and pressure, the kinematic viscosity for the Reynolds number, the specific heat for heating and cooling, and the vapor pressure to check pump suction.
- For temperatures between rows, interpolate in a straight line; the values vary smoothly.
Worked example: Reynolds number of 60 C water in a 50 mm pipe at 1.5 m/s
- At 60 C the kinematic viscosity is 0.4750 mm²/s (4.750E-7 m²/s).
- Re = V × D ÷ ν = 1.5 × 0.05 ÷ 4.750E-7 = 157 900, so the flow is turbulent (Re above about 4 000).
- At 20 C the viscosity is 1.0038 mm²/s, more than twice as high, so the same pipe and speed give a Reynolds number of only 74 700.
Notes and cautions
- Water is densest near 4 C (999.97 kg/m³); the table starts at 0 C, where ice would begin to form.
- Vapor pressure at 100 C equals atmospheric pressure, which is why water boils there at sea level. At altitude it boils at a lower temperature.
- These are properties of pure water. Brines, glycol mixes and dissolved solids change density, viscosity and specific heat.
Related tools and guides
- Pipe Flow and Pressure Drop Calculator
- Fluid Properties and Fluid Statics (guide)
- Steam and Water Property Tables (guide)
- All reference tables
FAQ
What is the density of water?
About 998 kg/m³ at 20 C (62.3 lb/ft³). It falls to about 958 kg/m³ at 100 C.
What is the specific heat of water?
About 4.18 kJ/kg·K (1 BTU/lb·°F) over the whole liquid range, which is unusually high and is why water is such a good coolant.
Why does viscosity matter?
It sets the Reynolds number, which decides whether flow is smooth or turbulent, and so the pressure drop in a pipe and the heat transfer coefficient.
Sources
- CRC Handbook of Chemistry and Physics; IAPWS-95 formulation for water properties; vapor pressure from the Hyland-Wexler equation.
- Liquid water near atmospheric pressure, typical handbook values (CRC Handbook, IAPWS). Vapor pressure from the Hyland-Wexler equation.