Last updated: 30 September 2026

What CalcEngines is

CalcEngines publishes calculators and converters for medicine, finance, electronics, mechanical engineering, fluid dynamics and general unit conversion. Every page states the formula it uses, works an example through with the figures on screen, and cites the standard, textbook or datasheet the method came from.

The site is a reference and educational tool. It is not a professional service, and using it does not create any professional relationship between you and CalcEngines.

The limits that apply to every page

A calculator answers the question it was given, not the question you are facing. It cannot see your context, your constraints, or anything you did not type in. Judging whether the method fits your situation is your responsibility, and it is the part a calculator cannot do for you.

Every result depends entirely on what you enter. A value entered in the wrong unit, a reference range from the wrong source, or an assumption that does not hold will produce an answer that looks completely normal and is completely wrong.

We check our work, and we still find errors. Formulas here are re-derived from primary sources rather than copied from other websites, and each vertical carries an automated test suite that runs thousands of checks before anything is published. That process regularly finds mistakes — including mistakes printed in published references — and we correct them when we find them. It does not make the site error-free. Check anything that matters against an independent source before you act on it.

Standards and data change. Reference intervals, tax rules, safety limits, material grades and published constants are all revised over time. A page reflects the sources available when it was written or last reviewed.

If you find an error, please tell us. We would rather hear about it than not.

Medical and laboratory calculators

Nothing on this site is medical advice, and it is not a substitute for clinical judgement. The medical pages are written for healthcare professionals, students and educators, and for patients who want to understand a result they have already been given.

• Do not use these pages to diagnose, treat or make a treatment decision. Discuss any result with a qualified clinician who knows your case.
• Reference intervals are not universal. They vary with the laboratory, the assay, the analyser, the population, age, sex and pregnancy. Always use the reference interval printed on your own laboratory’s report in preference to any figure shown here.
• Unit conversions depend on the analyte. A conversion factor relies on a molar mass or an assay-specific constant, and some analytes have no single agreed factor. Verify against your laboratory’s own stated units.
• Dosing and infusion calculators must never be used alone. Any dose must be checked independently by a qualified prescriber or pharmacist against the current product information before administration.
• Scores and interpretive tools are decision aids, not decisions. They were derived in particular populations and may not transfer to yours.
• These pages are not individually reviewed by a named clinician. Where a page carries a reviewer’s name, that person reviewed that page; where it does not, none has. We would rather say so than imply otherwise.

Finance calculators

Nothing on this site is financial, investment, tax or legal advice. We are not licensed financial advisers, tax practitioners or brokers, and no result here is a recommendation to borrow, invest, buy or sell anything.

• Figures are illustrative. Your lender’s or insurer’s own schedule, terms and fees govern what you will actually pay or receive. Rounding conventions, day-count bases and fee treatment differ between institutions and will change the answer.
• Tax and regulation vary by country and change frequently. Rates, slabs, exemptions and limits are those we believed current when the page was written.
• Projections are arithmetic, not forecasts. A compounding calculation assumes a return you supplied. Investments can lose value, and past performance does not indicate future results.
• Zakat and other religious calculations follow a stated method. Rulings differ between schools and scholars on nisab, on what is zakatable and on valuation. Treat the result as a working figure and consult a scholar you trust.

Before a decision involving significant money, take advice from a qualified professional who is regulated in your jurisdiction and knows your circumstances.

Electronics calculators

• Mains and building wiring must be designed and installed by a qualified electrician working to your local wiring regulations. Cable sizing, breaker selection, earthing and protective device coordination are code-governed and jurisdiction-specific. Use these pages to understand the arithmetic, not to replace the code or the electrician.
• Component ratings come from the manufacturer’s datasheet, at your actual temperature, voltage and duty. Always derate. A calculation that says a part is adequate at room temperature says nothing about it inside a hot enclosure.
• EMC results here are estimates for design guidance. Compliance with EMC, RF or safety standards is demonstrated only by testing at an accredited laboratory.
• Battery, charging and power-conversion calculations ignore failure modes — thermal runaway, protection circuits, cell imbalance — that dominate real safety.

Mechanical engineering calculators

These pages produce preliminary design figures. They are not a design, and they are not a substitute for a qualified engineer or for the governing standard.

• Material properties vary with supplier, heat treatment, section size, direction and temperature. A handbook value is a starting point, not a guarantee of what is in your hand.
• Choosing a safety factor is engineering judgement. It depends on consequence of failure, load uncertainty, inspection regime and duty cycle. We cannot choose it for you, and a default value on a page is not a recommendation for your application.
• Where a page cites ISO, ASME, AGMA, DIN or a similar standard, it cites the clause and computes what is computable. The standard itself governs. Where printed values are shown, they are attributed to a named manufacturer or distributor catalogue and you should confirm them against the actual part.
• Lifting, pressure, structural and load-bearing applications — anything where a failure could injure someone — must be checked and signed off by a competent engineer against the applicable code.
• Fatigue, stress concentration, misalignment, wear and dynamic loading are simplified or omitted on many pages. Where a page states its assumptions, those assumptions are the limit of what it knows.

CFD and simulation calculators

These pages help you set up and sanity-check a simulation. They do not validate one.

• Empirical correlations have ranges of validity, and different sources disagree within them. Where we know the spread, we print it. Outside its stated range, a correlation can be wrong by tens of per cent while looking entirely plausible.
• Cell counts, memory and runtime are order-of-magnitude estimates. A factor of two either way is normal, and geometry, mesh quality and solver settings move them.
• A converged simulation is not a correct one. Grid convergence and verification measure numerical error only. They say nothing about whether the physics, boundary conditions or turbulence model represent reality.
• Certification, safety-critical and regulatory work requires validation against experiment and the quality process your industry demands. Nothing here substitutes for that.

Unit converters

• Unit definitions vary by region and by era. A US pint is not an imperial pint; a “cup” differs between countries; traditional land, gauge and sizing units vary locally and sometimes village to village. Where a spread exists we show it rather than picking one value.
• Cooking and food-safety pages: safe internal temperatures and times exist to prevent foodborne illness. Follow your national food safety authority’s current guidance, and use a calibrated probe thermometer.
• Clothing, shoe and fastener sizing is manufacturer-specific. Any chart is an approximation; the maker’s own chart wins.
• Noise, radiation and exposure pages may reference legal limits. Those limits are set by your national regulator and are the authority — not this site.
• Calendar converters follow the tabular or arithmetic rule stated on the page. Observed religious calendars depend on local sighting and official announcement, and can differ from any calculated date by a day.

External links and advertising

We link to standards bodies, manufacturers and reference sources. We do not control those sites and are not responsible for their content or accuracy.

This site carries advertising. Advertising has no influence on the formulas, sources or conclusions on any page. Adverts are served by third parties and are not endorsements by CalcEngines.

Limitation of liability

The content on this site is provided “as is”, without warranty of any kind, express or implied, including as to accuracy, completeness or fitness for a particular purpose. To the fullest extent permitted by law, CalcEngines and its operator accept no liability for any loss, injury, damage or cost arising from use of, or reliance on, anything published here.

Nothing in this disclaimer excludes or limits liability that cannot lawfully be excluded or limited.

Contact

Questions, or an error to report: contact@calcengines.com. Corrections are welcome and are acted on.