Percentage guides and resources

Short, practical explanations of the maths behind every calculator on this site — written for shoppers, students and anyone who has to report a number in a meeting.

Basics · 5 min read

How to calculate percentages

The one rule behind every percentage question, explained with plain arithmetic.

Reference · 6 min read

Percentage formulas explained

Every formula this site uses, written out with a worked example each.

Everyday · 7 min read

Real-world percentage examples

Shopping receipts, salary rises, exam scores and restaurant bills.

Business · 8 min read

Business percentage calculations

Margin versus markup, month-over-month growth and churn.

Money · 6 min read

Finance and shopping percentage guide

Interest, stacked discounts, VAT and why 50% off then 20% off is not 70%.

Study · 9 min read

Student maths resources

Practice questions, mental-maths shortcuts and exam-style working.

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