About

Calculators Free offers free online calculators and converters: percentages (a percent of a number, percent change, percent increase and decrease, percentage difference, fractions and grades), everyday money sums (discounts, sales tax, tips, markup and margin), temperature conversion, and unit converters for length, weight, energy, power, frequency, voltage and current.

Each calculator gives the answer as you type and shows the arithmetic step by step, so you can check it or learn how to do it by hand. Nothing you type is sent anywhere: the sums run in your browser.

The site is written and kept by the Calculators Free Editorial Team. Read how we check the calculators on How we verify, the rules we follow on Editorial policy, and report a mistake on the contact page. Confirmed fixes are listed on Corrections.

In November 2026 we replaced about 2,900 near-identical single-answer pages with full calculators, and moved the old addresses to the calculator that answers the same question. The pages that people still found most useful stayed at their addresses as worked answers.