Quick calculators
Percentages, VAT, loans and more: straightforward calculators that show their working.
Quick percentage
All calculators
- Percentage calculator X% of Y, what percent, percentage change, and adding or removing a percentage.
- VAT calculator Add or remove VAT at your country's rate, or any rate you choose.
- Discount calculator Sale prices and savings, including stacked discounts.
- Loan calculator Monthly payments, total interest and a full amortization schedule.
- Compound interest calculator How savings grow with interest and regular deposits.
- Average calculator Mean, median, mode, range and standard deviation of a list of numbers.
- BMI calculator Body mass index in metric or imperial units, with the healthy weight range.
About MathyBit
Calculators that show their working
Everyday numbers shouldn't need a spreadsheet. MathyBit gives you one focused calculator for each common job, with results that update as you type.
Each calculator also explains the formula behind it, with a worked example, so you can check the answer, do it yourself next time, or explain it to someone else. No sign-up, no clutter, and nothing you enter leaves your browser.
The money calculators (VAT, discounts, loans and savings) give estimates for guidance. Always check real offers with your bank, lender or accountant.
Frequently asked questions
Are the calculators free?
Yes, completely. There is nothing to sign up for, and the site is paid for by ads in clearly marked spaces.
How accurate are the results?
The math is exact; results are rounded only for display, usually to two decimal places for money. Every calculator shows the formula it uses so you can check the result yourself.
Can I rely on the loan and savings results?
Use them as guidance. They show how the numbers work, but real offers include fees, taxes and terms that differ between lenders and banks. They are not financial advice.
Which currency do the calculators use?
Any. MathyBit works with plain numbers, so enter amounts in your own currency and read the results in the same one.
Is anything I enter stored?
No. All calculations run in your browser. Nothing you type is sent to a server or saved.