Free Online Calculators
Some questions just need a quick, trustworthy number: what's the monthly payment on this loan, how many days until that deadline, what's 18% of this total, how many kilometres is that. Our calculators answer them instantly and accurately, without the ad-choked interfaces that plague most calculator sites. This guide gathers them in one place so you can find the right one fast.
All calculators tools
Guides & tutorials
Percentage Calculator Formula: Formulas and Worked Examples
Learn the percentage calculator formula for percentages of a number, percentage increase and decrease, and percentage difference with clear worked examples.
5 min readUnit Conversion Made Simple: Metric, Imperial, and Everything Between
A practical guide to converting length, weight, temperature, and more — the formulas worth knowing, the conversions people get wrong, and a free tool that does it all.
6 min readHow to Calculate Your Loan EMI (With Worked Examples)
Understand exactly how a loan or mortgage monthly payment is worked out, what drives the total interest you pay, and how to model it all instantly for free.
Frequently asked questions
Are the calculator results free?
Yes. The calculators are free to use without an account or installation.
Can I check the working behind a result?
The calculator pages explain the relevant formula and show how the values produce the result.
Which calculator handles percentage change?
Percentage Calculator includes percentage-of, increase/decrease, and add/subtract modes.