Water Properties Table — Density, Viscosity & Vapor Pressure (0–100 °C)
Saturated liquid water from 0–100 °C: density, dynamic and kinematic viscosity, and vapor pressure — steam-table values cross-checked against NIST/IAPWS.
Updated August 18, 2026
Between freezing and boiling, water is anything but constant: density peaks near 4 °C and then falls about 4%, vapor pressure climbs by a factor of 165, and viscosity drops more than sixfold — hot water flows through a pipe with a fraction of the friction of cold water. This table gives the saturated-liquid values engineers actually plug in: ρ for mass and head conversions, μ and ν for Reynolds numbers and friction factors, and Pv for cavitation checks.
The density and vapor-pressure columns are rendered directly from the same steam-table data our NPSH margin calculator uses, so the chart and the calculator always agree; those values are IAPWS-consistent within 0.1%. Dynamic viscosity follows the Cengel property tables (Sengers & Watson correlation), verified against the NIST WebBook. The kinematic column is computed as ν = μ/ρ from the two columns beside it, never transcribed — which is why it agrees with published ν tables to the last digit.
Two habits worth keeping: use the temperature of the actual operating fluid (a chilled-water loop at 7 °C is 40% more viscous than a condenser loop at 40 °C, which moves Reynolds number and pressure drop by the same factor), and treat the vapor-pressure column as the hard floor in suction-side calculations — once local pressure touches Pv, the water flashes and the pump cavitates.
Saturated Liquid Water, 0–100 °C
| T (°C) | ρ (kg/m³) | μ (mPa·s) | ν (mm²/s) | Pv (kPa) |
|---|---|---|---|---|
| 0 | 999.8 | 1.792 | 1.792 | 0.6113 |
| 5 | 1000.0 | 1.519 | 1.519 | 0.8721 |
| 10 | 999.7 | 1.307 | 1.307 | 1.2276 |
| 15 | 999.1 | 1.138 | 1.139 | 1.7051 |
| 20 | 998.2 | 1.002 | 1.004 | 2.339 |
| 25 | 997.0 | 0.891 | 0.894 | 3.169 |
| 30 | 995.7 | 0.798 | 0.801 | 4.246 |
| 40 | 992.2 | 0.653 | 0.658 | 7.384 |
| 50 | 988.0 | 0.547 | 0.554 | 12.349 |
| 60 | 983.2 | 0.467 | 0.475 | 19.94 |
| 70 | 977.8 | 0.404 | 0.413 | 31.19 |
| 80 | 971.8 | 0.355 | 0.365 | 47.39 |
| 90 | 965.3 | 0.315 | 0.326 | 70.14 |
| 100 | 958.4 | 0.282 | 0.294 | 101.33 |
Saturated-liquid values; below ~50 °C they are indistinguishable from 1 atm compressed-liquid values for engineering purposes. ν = μ/ρ is computed, not transcribed (1 mm²/s = 1 cSt = 10⁻⁶ m²/s). Pv is absolute saturation pressure — water boils where system absolute pressure falls to Pv, which is why 100 °C shows 101.33 kPa (1 atm).
Sources & Further Reading
- Cengel & Cimbala, Fluid Mechanics: Fundamentals and Applications, 3rd Ed., Table A-3 / Cengel & Ghajar, Heat and Mass Transfer, Table A-9 — Properties of saturated water (viscosity basis: Sengers & Watson 1986)
- NIST Chemistry WebBook, Thermophysical Properties of Fluid Systems (IAPWS-95 formulation) — cross-check for density, viscosity, and saturation pressure
- Density and vapor pressure rendered from the NPSH margin calculator’s verified steam table (Cengel/IAPWS-consistent)
Frequently Asked Questions
Why does the density column say 999.8 at 0 °C instead of 1000?
Liquid water is densest at about 3.98 °C (999.97 kg/m³) and is very slightly lighter both colder and hotter — at 0 °C it is 999.8 kg/m³, still liquid, sitting above the ice it would form at 916.8 kg/m³. The round number 1000 kg/m³ is fine for hand checks; the table digits matter when you are converting precise pressure heads or calibrating instruments.
What is the difference between dynamic and kinematic viscosity?
Dynamic viscosity μ measures the fluid’s internal resistance to shear (Pa·s); kinematic viscosity ν = μ/ρ folds density in (m²/s) and is what appears in the Reynolds number Re = V·D/ν. In this table μ is in mPa·s (numerically equal to the old centipoise) and ν in mm²/s (equal to centistokes), so water at 20 °C is almost exactly 1 cP and 1 cSt.
How do I use the vapor-pressure column for pump cavitation checks?
NPSH available = (absolute suction pressure head) − (vapor pressure head) at the pumping temperature. Convert Pv to head with h = Pv/(ρ·g): at 80 °C that is 47.39 kPa ÷ (971.8 × 9.807) ≈ 5.0 m of head gone before you start. This is why hot-water and condensate pumps cavitate so much more easily than cold-water pumps — the NPSH margin calculator runs this exact table.
Do these values change with pressure, say in a 10-bar system?
Barely, for the liquid: water is nearly incompressible, so at 10 bar and 20 °C density rises only about 0.05% and viscosity is essentially unchanged — saturated-liquid values are standard practice for pressurized loops. Vapor pressure is a function of temperature only; higher system pressure does not lower Pv, it just gives you more margin above it.
Try the Calculators
Water Properties Table — Density, Viscosity & Vapor Pressure (0–100 °C) — reuven.tools/reference/water-properties — verified against: Cengel & Cimbala, Fluid Mechanics: Fundamentals and Applications, 3rd Ed., Table A-3 / Cengel & Ghajar, Heat and Mass Transfer, Table A-9 — Properties of saturated water (viscosity basis: Sengers & Watson 1986); NIST Chemistry WebBook, Thermophysical Properties of Fluid Systems (IAPWS-95 formulation) — cross-check for density, viscosity, and saturation pressure; Density and vapor pressure rendered from the NPSH margin calculator’s verified steam table (Cengel/IAPWS-consistent)