About calculators.dev

calculators.dev is a focused collection of calculators that finish the job — clear inputs, an accurate result, and an honest explanation of how that result was reached. We would rather ship fewer tools that are correct than many that are not.

How we keep results trustworthy

Trust comes from method, not marketing. A few principles guide every calculator on the site:

• Cited constants and sources. Where a formula relies on a standard constant or reference value, we name the source so you can check it yourself.
• Tested formulas.Each calculator's worked example is its literal unit-test fixture — the build fails if the math drifts from the example we publish.
• Transparent assumptions. We surface the assumptions and limitations of a calculation on its own page, rather than hiding them.
• Privacy by default. Your inputs are computed in your browser and never sent to a server.

What results are — and are not

Calculator results are estimates to inform a decision, not professional advice. For high-stakes situations we encourage you to verify the result and consult a qualified professional. See our disclaimer and terms of use for details.

Get in touch

Spotted a problem or have a suggestion? Visit our contact page.