Math Calculators
Quick, exact answers to everyday maths — percentages of a number, percentage change, and part-to-whole ratios.
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Math calculators
About these math calculators
Percentages show up in discounts, exam scores, pay rises, tax, tips, and growth figures — and they are easy to get subtly wrong. These math tools do the arithmetic exactly and show the formula they used.
Each calculator explains the method in plain language with worked examples, so you can check the logic yourself and reuse it in a spreadsheet when you need to.
Tips for accurate results
- Pick the right question type. “What is 20% of 500?” and “20 is what % of 500?” are different problems with very different answers.
- Order matters for % change. Enter the starting value first. Going from 100 to 150 is +50%, but going back from 150 to 100 is only −33.3%.
- Percentages compound. Two successive 10% discounts are a 19% total discount, not 20%, because the second applies to the reduced price.
FAQ
Math calculator questions
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