Find your steam state
Pure water / steam. Pressure range: 1 kPa–10 MPa absolute (0.01–100 bar absolute). Saturated temperatures are about 6.97–311°C. Superheated steam is supported above its saturation temperature, up to 800°C.
Absolute pressure = gauge pressure + local atmosphere. Standard atmosphere is the default; adjust for local conditions.
0% = saturated liquid; 100% = dry saturated vapor. Quality is not a volume fraction.
Steam properties
Mixture at the selected steam quality
| Property | Value |
|---|
Saturated-steam quick reference
Pressure is absolute. Subscript f means saturated liquid; g means dry saturated vapor; hfg = hg − hf.
| P (bar abs) | Tsat (°C) | hf (kJ/kg) | hfg (kJ/kg) | hg (kJ/kg) | vg (m³/kg) |
|---|---|---|---|---|---|
| 0.1 | 45.808 | 191.81 | 2392.07 | 2583.89 | 14.670558 |
| 0.5 | 81.317 | 340.48 | 2304.74 | 2645.21 | 3.240149 |
| 1.0 | 99.606 | 417.44 | 2257.51 | 2674.95 | 1.694023 |
| 1.01325 | 99.974 | 418.99 | 2256.54 | 2675.53 | 1.673295 |
| 2.0 | 120.212 | 504.68 | 2201.56 | 2706.24 | 0.885735 |
| 5.0 | 151.836 | 640.19 | 2107.92 | 2748.11 | 0.374804 |
| 10 | 179.886 | 762.68 | 2014.44 | 2777.12 | 0.194349 |
| 20 | 212.385 | 908.62 | 1889.76 | 2798.38 | 0.099581 |
| 50 | 263.943 | 1154.5 | 1639.73 | 2794.23 | 0.039446 |
| 100 | 310.999 | 1407.87 | 1317.61 | 2725.47 | 0.018034 |
Which steam properties should I use?
- Condensing dry saturated steam: if it leaves as saturated liquid at the same pressure, available heat per unit mass is hfg, not hg.
- Wet steam: h = hf + x·hfg, with x as a mass fraction. Density is 1 / [(1 − x)vf + xvg], not a weighted average of the two densities.
- Superheated steam: enter both absolute pressure and actual temperature. Heat released to a specified condensate outlet is the inlet-minus-outlet enthalpy difference.
- Steam flow from duty: mass flow = heat duty / available enthalpy drop. In SI, kW divided by kJ/kg gives kg/s. Account separately for condensate cooling, losses, and inlet wetness.
Heat duty calculator · Liquid-water properties
The existing heat exchanger calculator assumes single-phase streams with specified cp. It does not model condensation. Do not represent latent heat by entering an artificially large cp.
Limits and common mistakes
Gauge pressure is not absolute pressure. Temperature alone identifies a state only on the saturation curve. At saturation, pressure and temperature alone do not determine quality.
No mixture cp is reported: boiling at constant pressure is a phase change, not single-phase sensible heating. The saturated liquid and vapor cp values are single-phase limits. The mixture specific volume assumes equilibrium phases; it is not a two-phase pipe pressure-drop model.
This page excludes compressed-liquid lookup, pressures above 10 MPa, supercritical states, temperatures above 800°C, and transport properties such as viscosity. Use a full property package for those conditions. Enthalpy and entropy use the IF97 reference convention; compare values using the same convention.
Sources and method
Equations and numerical coefficients from IAPWS R7-97(2012), Revised Release on the Industrial Formulation 1997. Attribution: International Association for the Properties of Water and Steam. The page evaluates Regions 1 and 2 for phase properties and Region 4 for saturation. Saturation temperature is solved from the pressure equation.
Calculations use MPa absolute and kelvin internally. Displayed values are rounded. US energy conversions use the International Table Btu; density uses lbm. Equations are evaluated directly, without interpolating a coarse steam table.
Sources checked September 28, 2026. The page’s supported range is narrower than the complete IF97 formulation.