Steam97 Excel Add-In

Steam Tables for Excel based on IAPWS-IF97 (32 bit & 64 bit)

For Excel 2003 / 2007 / 2010 (32 bit & 64 bit) / 2013 (32 bit & 64 bit) / 2016 (32 bit & 64 bit)

Steam97 Excel Add-In

About Steam 97 Excel Add-In

The Steam97 Excel Add-In library calculates 30 thermodynamic and transport properties of water and steam in SI and English units.

It allows 16 different combinations of input variables to be used for calculations.

Input variables that can be used are:

  • Pressure
  • Temperature
  • Enthalpy
  • Entropy
  • Volume
  • Internal energy
  • Steam quality

The library is fully integrated in Excel, and available functions can be used in the same way as any other Excel function.

Main features of the library:
  • Professional quality, industrial strength software
  • Based on the international standard formulation
  • Accurate and thoroughly tested
  • Developed in C++ for maximum speed
  • Extend the library with User Defined Functions (UDF)
  • Call Steam97 functions from VBA (samples are included in the release version)
  • Easy to install and easy to use
  • For installation and use of the library no administrator rights required
  • After installation no computer restart required
  • One year free technical support

The following figure shows a sample spreadsheet included in the download package.

Steam97 Excel Add-In

Steam97 Excel Add-In - Sample calculations in Excel

Used Formulations

The library uses new industrial formulation for steam tables, called "IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam (IAPWS-IF97)", and replaces the previous industrial formulation for steam tables, IFC-67.

IAPWS-IF97 improves significantly both accuracy and speed of the calculation of the thermodynamic properties compared with the old formulation.

For transport properties calculations are based on the latest internationally accepted equations also available from IAPWS.

The Steam97 Excel Add-In libraries cannot be shipped to a third party as a part of your VBA application. If you need a royalty free library please refer to the Steam97 ActiveX DLL.

System Requirements

Operating system Windows XP / Vista / Windows 7 / Windows 8 / Windows 8.1 / Windows 10.

Excel 2003 / 2007 / 2010 (32 bit & 64 bit) / 2013 (32 bit & 64 bit) / 2016 (32 bit & 64 bit).

User privileges
Installation and use of the library requires standard user privileges or better.

Steam Properties

The following thermodynamic and transport properties can be calculated with Steam97 Excel Add-In:

Calculable properties in SI or E units - Steam97 Excel Add-In v3.1
  1 Pressure
  2 Temperature
  3 Density
  4 Specific volume
  5 Specific enthalpy
  6 Specific entropy
  7 Specific internal energy
  8 Specific isobaric heat capacity
  9 Specific isochoric heat capacity
 10 Speed of sound
 11 Isentropic exponent
 12 Specific Helmholtz free energy
 13 Specific Gibbs free energy
 14 Compressibility factor
 15 Steam quality
 16 Region
 17 Isobaric volume expansion coefficient
 18 Isothermal compressibility
 19 Partial derivative (dV/dT)p
 20 Partial derivative (dV/dP)T
 21 Partial derivative (dP/dT)v
 22 Partial derivative (dP/dV)T
 23 Isothermal Joule-Thomson coefficient
 24 Joule-Thomson coefficient
 25 Dynamic viscosity
 26 Kinematic viscosity
 27 Thermal conductivity
 28 Thermal diffusivity
 29 Prandtl number
 30 Surface tension

Range of Validity

The entire set of equations of the IAPWS-IF97, used by the library for calculation of thermodynamic properties, is defined by the following temperature and pressure range:

  • 273.15 K <= T < = 1073.15 K    p < = 100 MPa
  • 1073.15 K < T < = 2273.15 K    p < = 50 MPa

Steam97 Range of Validity

Fig.1 Steam table regions defined in the IAPWS-IF97


The following screenshots demonstrate how to use the library, it's a 4 step process.

1.(a) Start Excel and press the "Insert Function" toolbar button.

Insert Function toolbar button

1.(b) Alternatively, start Excel and press the "Insert Function" menu item.

Insert Function menu item

2. Select a Steam97 library (SI or English units).

Select Steam97 library

3. Select a function and press the OK button.

Select Function - Steam97 library

4. Enter input parameters and press the OK button.

Calculate Steam97 properties

NOTE: You don't have to put quotes around the property ID, they are inserted automatically.

That's it, the result will be displayed in the selected cell.

Steam97 VBA Programming

The release version of the Steam97 Excel Add-In library contains "modCallFunction" module which provides VBA wrapper utility functions.

The utility function CallFunction makes it easy to call Steam97.xll functions from VBA. For more information please refer to the help file provided in both demo and release versions.

Example 1

This excerpt from the code demonstrates how to calculate heat of evaporation for given saturation temperature.

  1. 'Calculate saturation pressure for given temperature
  2. ps = CallFunction("SatTXsi", t, xLiquid, "p")
  3. Worksheets("Heat of Evaporation").Cells(row, 2).Value = ps
  4. 'Calculate specific enthalpy of the liquid on the saturation line
  5. hLiquid = CallFunction("SatTXsi", t, xLiquid, "h")
  6. Worksheets("Heat of Evaporation").Cells(row, 3).Value = hLiquid
  7. 'Calculate specific enthalpy of the vapor on the saturation line
  8. hVapor = CallFunction("SatTXsi", t, xVapor, "h")
  9. Worksheets("Heat of Evaporation").Cells(row, 4).Value = hVapor
  10. 'Calculate heat of evaporation
  11. delta_h = hVapor - hLiquid
  12. Worksheets("Heat of Evaporation").Cells(row, 5).Value = delta_h

Example 2

This excerpt from the code demonstrates how to calculate steam turbine efficiency.

  1. 'Calculate specific enthalpy
  2. hIn = CallFunction("SteamPTsi", pIn, tIn, "h")
  3. Worksheets("Steam Turbine").Cells(row, 3).Value = hIn
  4. 'Calculate specific entropy
  5. sIn = CallFunction("SteamPTsi", pIn, tIn, "s")
  6. Worksheets("Steam Turbine").Cells(row, 4).Value = sIn
  7. Worksheets("Steam Turbine").Cells(row, 5).Value = pOut
  8. Worksheets("Steam Turbine").Cells(row, 6).Value = tOut
  9. 'Calculate specific enthalpy
  10. hOut = CallFunction("SteamPTsi", pOut, tOut, "h")
  11. Worksheets("Steam Turbine").Cells(row, 7).Value = hOut
  12. 'Calculate specific enthalpy
  13. hs = CallFunction("SteamPSsi", pOut, sIn, "h")
  14. Worksheets("Steam Turbine").Cells(row, 8).Value = hs
  15. 'Calculate steam turbine efficiency
  16. eta = (hIn - hOut) / (hIn - hs) * 100
  17. Worksheets("Steam Turbine").Cells(row, 9).Value = eta


The setup program will automatically install the library in Excel.

To install the library successfully you must have at least standard user privileges on your computer.

Steam97 Excel Add-In library

For Excel 2003 / 2007 / 2010 (32 bit) / 2013 (32 bit) / 2016 (32 bit)

- Download Steam97 Excel Add-In version (3.1) - demo (32 bit)

Steam97 Excel Add-In library

For Excel 2010 (64 bit) / 2013 (64 bit) / 2016 (64 bit)

- Download Steam97 Excel Add-In version (3.1) - demo (64 bit)

You can also evaluate the Steam Tables library (based on IAPWS-IF97) online, visit Steam Tables Calculator web application. It uses the same calculation engine as the Steam97 Excel Add-In.

Quick reference documents

- List of available properties in Steam97 Excel Add-In

- List of available functions in Steam97 Excel Add-In

Steam diagrams

- logP-H diagram in SI units generated with Steam97 Excel Add-In

Price info

Prices subject to change without notice!

A license includes 32 bit and 64 bit version of the library.

Steam97 Excel Add-In version 3.1
1-4 licensesUSD 249.95 per copy
5-20 licensesUSD 224.95 per copy
21 > licensesUSD 199.95 per copy
Company wide licenseUSD 9995.00


Each license also includes the following:

  • One year free e-mail technical support
  • One year free minor version updates if available (for example 3.2, 3.x up to, but not including version 4.0)

If you have any questions, please don't hesitate to contact sales at:

General Information

For quick access to the Steam97 Excel Add-In, you may purchase and download our product using automated and secure online ordering system. After ordering, you will receive a notification mail with further instructions, your password (required during installation) and the retail version download location.

The Registration includes a free subscription program. Each Registered user will be receiving bug fixes and technical support for the registered version within one year.

Shipping by the postal mail is not available.

How to order

1. Internet ordering

Available ordering options (open an order form to select):

  • Credit Card (Visa®, Mastercard®, American Express®, Discover®)
  • PayPal
  • Amazon

To buy a specific number of licenses for the Steam97 Excel Add-In click the button: Open order page for the Steam97 Excel Add-In or to purchase a Company Wide License contact sales at:

2. Bank Direct Payment

If you prefer to pay for the product by "Bank Direct Payment", contact sales at: