Percentage Calculator

Percentages turn up everywhere: discounts, tax, pay rises, exam marks, growth figures. This calculator covers the six questions people ask most, from "what is 15% of 200" to "by what percent did my traffic change", and shows the formula it used so you can check the working or repeat it in a spreadsheet.

How to use Percentage Calculator

1. Choose what you want to work out, for example What is X% of Y? or Percentage change from X to Y.
2. Enter the two numbers. The labels change to show which number goes where.
3. The answer appears as you type, with the formula underneath.
4. Click Copy results to paste the answer somewhere else.

When it comes in handy

• Working out a sale price or how much a discount saves.
• Reporting month-on-month growth in traffic, sales or followers.
• Checking a mark, a commission or a tip.

Frequently asked questions

What is the difference between percentage change and percentage difference?

Percentage change compares a new value with an old one, so the direction matters: 50 to 75 is a 50% increase, 75 to 50 is a 33.3% decrease. Percentage difference compares two values with no "before" and "after", dividing by their average, so the answer is the same either way round.

Why does a 20% rise followed by a 20% fall not get me back to the start?

Because the second percentage is taken of a bigger number. 100 plus 20% is 120; 120 minus 20% is 96. To undo a 20% rise you need a fall of about 16.7%.

How do I calculate a percentage in Excel or Google Sheets?

For X% of Y use =Y*X/100. For "X is what percent of Y" use =X/Y and format the cell as a percentage. For change from A to B use =(B-A)/A.