Percentage calculator
Percentages, worked out.
Choose a calculation. The result updates as you type and shows each step.
Calculator
Percent vs percentage points. If a rate rises from 4% to 5%, it went up by 1 percentage point, but by 25 percent (1 ÷ 4 × 100). Use percentage points when comparing two percentages directly.
What each calculation means
X% of Y finds a part of a whole, such as a 15% tip on an $80 bill. Percent change measures how far a value moved from where it started, so the starting value matters. Percent difference compares two values when neither one is the starting point, so it divides by their average. Price after discount takes a percentage off a price.
Formulas
Worked example
A jacket costs $120 and is 25% off. The saving is 120 × 25 ÷ 100 = $30, so you pay 120 − 30 = $90. If the same jacket had gone from $90 back up to $120, that is a change of (120 − 90) ÷ 90 × 100 = 33.33%, which shows why a 25% cut needs a 33.33% rise to undo it.
When to use it
- Use percent change for before-and-after figures, such as prices, rent or test scores.
- Use percent difference to compare two quotes, two measurements or two stores, where neither is the baseline.
- A percent change from 0 can’t be calculated, and the calculator tells you so instead of showing an error value.