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Steam table calculator (IAPWS-IF97)

Choose pressure, temperature or quality and get water and steam properties from the IAPWS-IF97 industrial formulation, with a diagram and a saturation table you can download as a spreadsheet.

Pre-sizing and estimating tool: results do not replace design, calculations or reports signed by a licensed professional, nor verification against the applicable codes and standards.

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State of interest

Range covered: 32 to 662 °F (0.01 to 350 °C) on saturation (up to about 2,400 psia) and superheated steam up to 1,472 °F (800 °C). The near-critical region (IF97 region 3) is not computed.

Table
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Temperature–entropy diagram

Water saturation dome, the isobar at the chosen pressure and the computed state.

Tap the chart to see the values.

Saturation temperature and latent heat

The higher the pressure, the hotter the steam and the less energy each kg releases when it condenses.

Tap the chart to see the values.

Saturated steam table

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Method, assumptions and references

Equations used

Region 1 (liquid) and region 2 (vapor): dimensionless Gibbs energy γ(π, τ); h = R T τ γτ, s = R (τ γτ − γ), v = R T π γπ ÷ p, cp = −R τ² γττ
Region 4 (saturation): IF97 equations 30 and 31 for psat(T) and Tsat(p)
Wet steam: h = hf + x · hfg; s = sf + x · (sg − sf); v = vf + x · (vg − vf)
R = 0.461526 kJ/(kg·K); absolute pressure = gauge + 14.696 psi

Assumptions and limits

  • Results were checked against the iapws Python library at every test point, agreeing to better than 1 part in 10⁹.
  • Region 3 (near critical, above 350 °C and about 2,400 psia) and region 5 (above 800 °C) are not computed.
  • Enthalpy and entropy are referenced to zero for saturated liquid at the triple point (0.01 °C), as in standard tables.

Standards and technical documents

  • IAPWS R7-97(2012): Revised Release on the IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam
  • Wagner, W.; Kretzschmar, H.-J. International Steam Tables, 3rd ed. Springer, 2019
  • ASME Steam Tables: Thermodynamic and Transport Properties of Steam (IAPWS-IF97), 8th ed.

U.S. regulations

  • ASME Boiler and Pressure Vessel Code, Section I and Section VIII, adopted by state boiler laws

Frequently asked questions

What is the temperature of steam at 150 psig?

At 150 psig (about 164.7 psia), saturated steam is at about 366 °F. Use saturation by pressure and pick gauge or absolute.

What is latent heat?

The energy released when 1 kg (or 1 lb) of steam condenses without changing temperature. It is what heats the process in exchangers and jackets, which is why steam should arrive dry.

What is the difference between saturated and superheated steam?

Saturated steam is at the boiling point for its pressure and condenses as it loses heat. Superheated steam is above it: it gives up sensible heat before condensing and is used in turbines and long lines.