Free, ad-supported calculators for construction, money, health and everyday math. No sign-up, no fluff.
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Every tool on InstantCalc, grouped by category. New calculators are added regularly.
InstantCalc gives you a growing library of fast, mobile-friendly calculators — no account, no downloads. Each tool runs entirely in your browser, so your numbers stay private and results appear the moment you type.
We cover the calculations people search for most: how much concrete or gravel a job needs, what a mortgage or car loan really costs, a BMI or calorie reading, your GPA, or a quick currency conversion across several countries at once. Every calculator includes a plain-English explanation and the formula behind it, so you understand the answer, not just see it.
Yes. Every calculator on InstantCalc is completely free and supported by unobtrusive ads.
No sign-up, no email. Open a tool and start calculating.
Each tool uses standard, documented formulas shown alongside the calculator. For legal, medical or financial decisions, treat results as estimates and consult a professional.