Percentage Calculator
Compute percent of a number, percent change, and inverse percent.
Three calculators in one: what is X% of Y; X is what percent of Y; and percent increase/decrease between two numbers. Useful for tips, tax, discounts and analytics.
Common use cases
- Calculate sales tax, VAT, and discount amounts on prices
- Compute tip on restaurant bills and split per person
- Measure month-over-month growth in analytics and KPIs
- Compute commission, markup and margin on sales transactions
Frequently asked questions
How is percent change calculated?▾
(new − old) / old × 100. A negative result means a decrease.
Why is going up 50% then down 50% not back to the original?▾
Because the bases differ: +50% on 100 = 150, then -50% on 150 = 75. Asymmetric percent changes don't cancel out — a common cause of finance/marketing-report errors.