International Steam Tables vs CNVRT
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
International Steam Tables
This application calculates thermodynamic properties of water and steam based on the IAPWS-IF97 formulation. It allows users to input various combinations of variables and automatically computes a wide range of properties, including transport properties and derivatives. Designed for students and engineers, it offers a comprehensive tool for thermodynamic calculations.
- Calculates thermodynamic properties of water and steam
- Based on IAPWS-IF97 formulation
- Supports various input variable combinations
- Automatically computes results
- Includes transport properties and derivatives
- Designed for students and engineers
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The "International Steam Tables - IAPWS-IF97" app has been developed by active members of the International Association for the Properties of Water and Steam (IAPWS) at the Zittau/Görlitz University of Applied Sciences. The research group at the Department of Technical Thermodynamics in Zittau participated in the development of the "Industrial Formulation IAPWS-IF97 for the Properties of Water and Steam" and developed four supplementary standards for backward equations. This universal app can be used on iPhone, iPad, and iPod touch, and is designed for comfortable use. The calculations of the thermodynamic properties are based on the Industrial Formulation IAPWS-IF97 and cover its full range of validity. In addition, transport properties, thermodynamic derivatives, and backward functions can be calculated. This app is intended to be used by students and engineers in their daily work. To learn more about the "International Steam Tables - IAPWS-IF97" app visit our website www.thermodynamics-zittau.de for a detailed User's Guide. --------------------------------------- Features of the "International Steam Tables - IAPWS-IF97" app: The following combinations of input variables can be chosen: Pressure p and temperature t Pressure p and vapor fraction x in wet steam region Temperature t and vapor fraction x in wet steam region Pressure p and specific enthalpy h Pressure p and specific entropy s Specific enthalpy h and specific entropy s Specific internal energy u and specific volume v Specific enthalpy h and specific volume v The user just edits the values of the input variables and all results are calculated automatically. See the screenshots below this text for details. Depending on the given pair of input variables the following properties will be calculated: Pressure p or saturation pressure ps Temperature t or saturation temperature ts Vapor fraction x Specific volume v Density rho Specific internal energy u Specific enthalpy h Specific entropy s Specific isobaric heat capacity cp Specific isochoric heat capacity cv Isentropic exponent kappa Speed of sound w Isobaric cubic expansion coefficient alpha_v Isothermal compressibility kappa_t Thermal conductivity lambda Dynamic viscosity eta Kinematic viscosity ny Prandtl number Pr Thermal diffusivity a The calculated properties are displayed in a scrollable view. The user just needs to scroll down to see all the results. See the screenshots below for details. If the user switches from one input variable combination to another the previously given or calculated values will be assigned to the new input values and the output is being calculated automatically. For example, if the user calculates a certain state point from pressure p and temperature t and switches to a calculation from pressure p and specific entropy s afterwards, the previously calculated value for s (from p and t) will be assigned as input value for s. This eases the calculation of thermodynamic processes in which one property is kept constant, e. g. of an isentropic expansion. The user can choose SI or I-P unit systems. In addition a variety of other units are available, e.g. K, °C, °F, °R for Temperature, MPa, bar, psi, atm for pressure, kg, lb for mass, kJ, Btu, ft lbf, kcal for energy. All units can be selected independently but the user might also switch between SI and IP unit system for all properties with just one tap. See the screenshots below this text for details. Unit conversions will be effective immediately. A detailed User's Guide explains the features and capabilities of this App. View the User's guide online on www.thermodynamics-zittau.de.
CNVRT
Instantly convert over 200 units across 20 measurement categories, from weight and length to temperature and data storage. This tool simplifies metric and Imperial conversions for STEM professionals and everyday users alike.
- Over 200 units supported
- 20 measurement categories
- Instant conversions
- Metric and Imperial units
- Optimized for Apple devices
- STEM and everyday use
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CNVRT allows you to convert any unit of measurement easily and instantly so you never have to do it yourself or struggle with metric and Imperial units. CNVRT supports over 200 different units and 20 different measurements, each with its own unique color. These measurements include: • Weight or Mass • Length or Distance • Temperature • Speed • Area • Time or Duration • Data Storage • Angle • … and many more! CNVRT is optimized for iPhone, iPad and macOS. Whether you are in STEM or just for everyday use, CNVRT will simplify your life.
Screenshots
Verdict
The clearest difference is rating: CNVRT at 4.5 against International Steam Tables's 3.9. CNVRT also leads on update cadence (every 2 weeks vs every 68 months). International Steam Tables's advantage is review sentiment (71% vs 50%) and price ($2.99 vs $4.99). On ratings volume, ads, in-app purchases and monetization model there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
International Steam Tables costs $2.99 and CNVRT $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.
CNVRT holds the better App Store score, 4.5 against 3.9. Both are backed by a comparable volume of ratings — 8 and 19 respectively. Written reviews complicate that: 71% of International Steam Tables's written reviews are positive against 50% of CNVRT's, so the app with the better star average is not the one people write more warmly about.
International Steam Tables ships an update every 68 months, CNVRT every 2 weeks. Both last shipped on October 24, 2026.
| Parameter | International Steam Tables | CNVRT |
|---|---|---|
| Price | $2.99 — better | $4.99 |
| Rating | 3.9 (8 ratings) | 4.5 (19 ratings) — better |
| Positive reviews | 71.4% of reviews — better | 50.0% of reviews |
| Number of ratings | 8 | 19 — better |
| Update frequency | Every 68 months | Every 2 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod, Mac — better |
| Requires iOS | 8.0 — better | 15.0 |
| Further details — not scored | ||
| Size | 10 MB | 1 MB |
| Age rating | 4+ | 4+ |
| Developer | Hans-Joachim Kretzschmar | Pascal Andraos |
Customer experience
International Steam Tables
CNVRT
In-app purchases
International Steam Tables
No in-app purchases
CNVRT
No in-app purchases
Questions
Is International Steam Tables free?
Is CNVRT free?
Which has better reviews, International Steam Tables or CNVRT?
Do International Steam Tables or CNVRT have ads?
Which is updated more often, International Steam Tables or CNVRT?
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