About Engineering Calculator Hub

What this site is

Engineering Calculator Hub is a free collection of engineering calculators for power plant, instrumentation, electrical, civil, and mechanical work — built to answer the kind of everyday sizing, checking, and verification questions engineers run into on the job, from short-circuit fault current and IDMT relay curves to boiler blowdown rate and SIL/PFDavg verification. It also includes a full SAMA logic diagram simulator with a real DCS-style multi-page architecture and a shared instrument tag database.

Who runs it

This site is built and maintained by Dr. Kundan.

Methodology — how a calculator here is actually built

Every calculator on this site is tagged with a confidence badge (visible at the top of the page) that honestly states how it was verified:

• Verified against published standard — checked against the named standard's own equations and, where one exists, a published worked example, not just internal self-consistency.
• Standard method — stated scope limits apply — a real, correct engineering method that deliberately doesn't cover every case the full standard does; the scope note in the result explains exactly what's excluded.
• Estimation / reference tool — gives an order-of-magnitude or typical-value result by design, not a substitute for a full study or OEM documentation.

Where a calculator uses generic reference figures rather than a specific manufacturer's proprietary data, that is stated directly in the page, not left implicit. None of these tools are a substitute for calibrated instruments, an approved design document, or qualified engineering review — see the disclaimer in the site footer.

How accuracy is checked

The calculation engine is covered by an automated test suite of several hundred checks that is run before every release. Tests compare results with published worked examples and, for the steam properties and ISO 5167 flow equations, with independent open-source implementations (python-iapws and python-fluids) to many significant figures. Where a calculator is outside the range of its equations — for example, steam in the near-critical region — it says so instead of returning a number.

Editorial policy and corrections

Guides and calculator notes are written to explain the engineering, state their assumptions and cite the standard or method used. If you find an error, send the calculator name, your inputs and the result you expected; confirmed corrections are made in the next release. Standards such as ISO 5167 and IAPWS-IF97 are referenced, not reproduced; for contractual or safety-critical work, consult the licensed standard.

How the site is funded

The calculators are free to use. The site is supported by advertising (Google AdSense) and optional voluntary donations. Advertising never affects a calculation result, and no result is hidden behind a paywall.

Have a question or feedback?

We’d love to hear from you. If you have any suggestions, find an issue with one of the calculators, or need assistance, feel free to contact us: admin@engineeringhubcalc.com.