EQS – Equation Solver
Solve engineering equations
Only for Mac
Free · In‑App Purchases
Mac
Type the equations of an engineering problem in any order. EQS solves them, with fluid properties, units checked, parametric tables and plots. Try it free for 14 days.
EQS solves the equations of engineering problems. Type the equations in any order, as you write them on paper: EQS finds which unknowns each equation gives, puts them in order and solves them, also when many equations must be solved together.
Made for thermodynamics, heat transfer, fluid mechanics and energy courses, and for the engineers who use these subjects every day.
EQUATIONS AND UNITS
• Type equations in any order; EQS finds the unknowns and solves them together where needed
• Units on every number, checked in each equation, with SI and English units side by side
• Arrays, functions, procedures, conditions and loops for larger models
• Formatted equations, which you can copy as LaTeX or as a picture
FLUID PROPERTIES
• Water, steam, refrigerants, air, gases and their mixtures, brines and incompressible liquids, from the open CoolProp library
• Humid air: psychrometric properties and the psychrometric chart
• Property plots (T-s, P-h, h-s, T-v and more) with the states of your cycle drawn on them
TABLES, PLOTS AND ANALYSIS
• Parametric tables: change one input over a range and see every result
• Plots with several curves, zoom, curve fits and export to SVG and PNG
• Optimisation, uncertainty and sensitivity analysis, and integration in time
CYCLES AND FLOWSHEETS
• A flowsheet window: draw pumps, turbines, heaters, condensers and feedwater heaters, and EQS writes the equations
• A library of components and of heat transfer and fluid flow correlations
MORE
• More than 40 worked examples, from a simple Rankine cycle to combustion and humid air
• A built-in guide that teaches EQS step by step
• Your models stay on your Mac; EQS needs no account and no internet connection
TRY BEFORE YOU BUY
EQS is free to download. It opens and shows models at any time. Start the free 14-day trial to solve without limits; then one purchase unlocks EQS for ever, with free updates. A licence file from your university also unlocks EQS.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Repairs, nothing new: - Right answers for equations whose terms are all very small, for units on property inputs and after the last number of a sum, and for check and sweep values with units. - Stiff time-dependent problems, integrals of plain functions, Bessel functions and complex numbers are more exact. - Print works and prints only the window; rename and other commands that ask a question work again. - Typing into a table cell replaces its value; the decimal comma works in every field. - Several long calculations at once no longer slow the rest of EQS; very deep models give an error instead of closing the app. - The results stated in the Guide and the examples agree with the solver.
The developer, stefan butucea, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- stefan butucea
- Size
- 20.2 MB
- Category
- Education
- Compatibility
Requires macOS 12.0 or later.
- Mac
Requires macOS 12.0 or later.
- Mac
- Languages
- English
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- 14-day Trial $0.00
- EQS Full Version $19.00
- Copyright
- © 2026 Stefan Butucea
