What a percentage calculator does
A percentage expresses a number as a fraction of 100. This calculator handles the everyday percentage questions people actually run into, from working out a discount at the checkout to measuring how much a value has grown, without you having to remember the formula each time.
The five calculations it covers
- Percentage of a value: Find what a given percentage of a number is, for example 20% of 150.
- Increase and decrease: Add or subtract a percentage from a value, useful for price rises, tips and reductions.
- Percentage change: Measure how much a number has grown or shrunk between an old and a new value.
- Discount: Enter an original price and a discount percentage to see the amount saved and the final price.
- Markup: Turn a cost price plus a markup percentage into a selling price.
- Ratio to percentage: Convert a fraction such as 3 out of 4 into a clean percentage.
How to use it
- Pick the tab that matches your question, Basic, Change, Discount, Markup or Ratio.
- Enter your numbers in the fields shown, then press Calculate or the Enter key.
- Read the result along with the calculation, so you can check the working at a glance.
Handy percentage tips
- To find a percentage of a number, multiply the number by the percentage and divide by 100.
- A percentage increase and the equivalent decrease are not symmetrical: a 50% rise followed by a 50% fall does not return you to the start.
- When comparing two figures, percentage change is measured against the original value, not the new one.