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Percentage Calculator
Work out percentages, percentage increase/decrease, and a percentage of a number.
Examples
🔗 Embed this calculator on your site
Copy the code and paste it into your HTML page — it displays a compact embedded percentage calculator (400×520 recommended).
📚 Percentage guides
- How to calculate percentages — the complete guide — A percentage is a way of describing "part of a hundred" — 25% is exactly 25 out of 100, or 0.
- Percentage of an amount — what is X% of Y — "What is X% of Y" is the most common percentage question in everyday life — a discount in a shop, a tip in a restaurant, VAT on a bill.
- Percentage discounts — what you actually pay — A "30% off" sign in a shop window looks simple, but there are two separate questions here: how much money you save, and how much you actually pay.
- Percentage change — increase and decrease — A percentage change describes how much a value has grown or shrunk, relative to its starting value — a share price, the number of pupils in a school, or the kilometres you ran this week compared with last week.
- Reverse percentages — finding the original amount — A reverse percentage question gives you the amount AFTER a percentage change and asks for the amount BEFORE it — the price before the sale, the bill before VAT, the salary before the rise.
- Compound interest — growth and decay with percentages — Compound interest means the interest is added to the account each year, and the next year's interest is worked out on the new, larger amount.
- Converting fractions, decimals and percentages — A fraction, a decimal and a percentage are three different ways of writing exactly the same number — a half, 0.
How to use it
- X% of Y — choose the first tab, enter a percentage and a value, and get how much X percent of Y is.
- What % is Y of X — second tab, enter the part (Y) and the whole (X), and get the percentage the part is of the whole.
- Percentage change from A to B — third tab, enter the original value (A) and the new value (B), and get the percentage increase or decrease.
- Every result comes with the formula, the substitution and a full explanation.
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✍️ Written by the MathsUK teamChecked against the National Curriculum and GCSE specifications