About 100+ Calculators
100+ Calculators is a free collection of online calculators for everyday tasks — 101 tools organized into six categories:
- Math
- Financial
- Health & Fitness
- Unit Conversion
- Date & Time
- Construction & Building
More than just a number
Every calculator page includes more than the calculator itself. Each one comes with a short guide on how to use it, real-world examples, answers to common questions, and a plain-English note about the formula behind the results — so you can understand what the number means, not just get it.
How the calculators work
All calculators run in your browser. The numbers you enter are processed on your own device — they are not stored on our servers or sent to third parties. There is nothing to install and no account needed.
Accuracy and limits
We build every calculator from well-known public formulas and explain them on the page. Still, results are estimates, affected by your inputs, assumptions, and rounding. For decisions that matter — a mortgage, a medical question, a building project — treat our results as a starting point and verify them with a qualified professional or official source. See our disclaimer for details.
Getting in touch
Spotted a calculation that looks wrong, or have an idea for a calculator that's missing? We'd like to hear about it — visit the contact page.