Quick Tools
BMI Calculator
Check your body mass index in metric or imperial units and see the healthy weight range for your height.
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Quick Tools
Everyday calculators you can open, use and close in under a minute - no sign-up, no app install, everything runs in your browser.
- 12 resources
- Free, no sign-up
- More added regularly
Quick Tools
Small calculators, ready to use
Each one opens straight into the tool. No accounts, no downloads, and nothing you type leaves your browser.
Quick Tools
Percentage Calculator
Work out a percentage of a number, what one number is as a percentage of another, and percentage change.
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Quick Tools
Age Calculator
Find your exact age in years, months and days, plus total days lived and the countdown to your next birthday.
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Quick Tools
Unit Converter
Convert length, weight, temperature, volume, speed and data sizes with live results and a swap button.
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Quick Tools
Tip Calculator
Work out the tip, the total and the amount per person, with rounding options for splitting a bill.
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Quick Tools
Percentage Increase Calculator
Calculate the percentage increase between two numbers, or increase a price, salary, or budget by a percentage.
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Quick Tools
Percentage Decrease Calculator
Find the percentage decrease between two numbers, or reduce any value by a percentage.
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Quick Tools
Discount Calculator
Work out the sale price, the amount you save and what stacked discounts are really worth.
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Quick Tools
EMI Calculator
Calculate your monthly instalment, total interest and total repayment for any loan.
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Quick Tools
Loan Calculator
See your monthly loan payment and how much time and interest an extra monthly payment saves.
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Quick Tools
Simple Interest Calculator
Calculate simple interest and the total amount for any principal, rate and period.
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Quick Tools
Compound Interest Calculator
See how savings grow with compounding and regular monthly contributions, year by year.
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How these tools are built
Every calculator here runs entirely in your browser using plain JavaScript. That means results appear as you type, the page works on a weak connection, and the numbers you enter are never sent to a server or stored anywhere.
Each tool also has an explanation underneath it: how the calculation works, where it is commonly misread, and which related tool you probably want next. The tool comes first and the reading is optional - the opposite of most calculator pages.
Frequently asked questions
How do I use a free online calculator without signing up?
Open any calculator, type your numbers into the fields and the result updates straight away. Everything runs in your browser, so there is no account to create and nothing you enter is uploaded.
How do I calculate a percentage, a loan payment or a discount quickly?
Pick the matching calculator: Percentage for percent of and percent change, EMI or Loan for monthly payments, and Discount for sale prices. Enter the figures and read the result and the worked formula underneath.