Steam tables (IAPWS-IF97) in zero-dependency JavaScript

Steam tables, statistical tables and unit conversion for engineering, in plain JavaScript with zero dependencies. Every function is checked by tests against published reference values.

The same code computes the printable tables on taueng.com: the saturated steam tables, the t-table, the chi-square table and the Z-table, the superheated steam tables, and an interactive steam calculator.

npm install engineering-tables

An ES module for Node 18+ and modern browsers, with TypeScript types included.

import { saturated, tsat, tCritical, chi2Critical, phi, convert } from 'engineering-tables'

// Saturated water and steam at 100 °C (T in kelvin, p in MPa) const s = saturated(373.15) s.p * 1000 // 101.418 kPa s.hfg // 2256.5 kJ/kg, enthalpy of vaporisation s.vg // 1.6719 m³/kg

tsat(1) - 273.15 // 179.89 °C, boiling point at 1 MPa tCritical(0.025, 10) // 2.228, two-sided 95% with 10 degrees of freedom chi2Critical(0.05, 10) // 18.307 phi(1.96) // 0.9750 convert('pressure', 30, 'psi', 'bar') // 2.0684

Functions

Function Returns

saturated(T) { T, p, vf, vg, hf, hg, hfg, sf, sg, sfg } at T in K (273.15 to 623.15 K)

psat(T), tsat(p) Saturation pressure (MPa) at T (K), saturation temperature (K) at p (MPa)

region1(T, p), region2(T, p) { v, h, s } for compressed liquid and for vapour

stateTP(T, p) Phase (liquid, vapour, or critical/range when not covered) with v, h, s at T in K and p in MPa

tCdf(t, df), tCritical(alpha, df) Student's t CDF, and t with P(T > t) = alpha

chi2Cdf(x, df), chi2Critical(alpha, df) Chi-square CDF, and x with P(X > x) = alpha

phi(z), erf(x) Standard normal CDF and the error function

convert(category, value, from, to) Unit conversion; UNITS lists the categories and units

Arguments outside the stated ranges throw a RangeError rather than return a number that looks right and is not.

Units: m³/kg, kJ/kg and kJ/(kg·K), with the IAPWS reference state (internal energy and entropy of saturated liquid are zero at the triple point).

npm test runs the checks: the IAPWS-IF97 verification tables for regions 1, 2 and 4, published t and chi-square critical values, the standard normal table and exact unit definitions.

The tables computed with this library are published as a citable CSV dataset on Zenodo: doi.org/10.5281/zenodo.23936027.

Mashiah, D. (2026). Engineering reference tables: saturated steam (IAPWS-IF97), Student's t, chi-square and standard normal values, and unit conversion factors. Zenodo. https://doi.org/10.5281/zenodo.23936027

To cite the software itself: Mashiah, D. (2026). engineering-tables. Zenodo. https://doi.org/10.5281/zenodo.23939106

David Mashiah, mechanical engineering student at Tel Aviv University. Built for taueng.com, free study tools for engineering students. MIT licensed.