Percentage Calculator

How to use the percentage calculator

1. Pick the calculation you need.
2. Enter the two numbers.
3. Read the answer and the working shown beneath it.

About this tool

Three different questions get called 'percentage', and mixing them up is the usual source of error. What is 15% of 240? What percentage of 240 is 36? And what is the change from 240 to 276? Each has its own formula, so this calculator keeps them separate and prints the arithmetic under each result.

Percentage change deserves particular care because it is not symmetric. A rise from 100 to 150 is +50%, but the fall from 150 back to 100 is −33.3%. The base you divide by is whichever value came first, and swapping them quietly changes the answer.

Common uses

• Applying a discount to a price.
• Calculating a tip or a commission.
• Reporting month-on-month growth correctly.

Frequently asked questions

What is the difference between percentage change and percentage points?

If a rate moves from 4% to 6%, that is a rise of 2 percentage points but a 50% increase. Financial and polling figures are usually quoted in points to avoid the ambiguity.

Why isn't a 20% rise cancelled by a 20% fall?

The second percentage is taken from a larger base. 100 rises to 120, then a 20% fall takes off 24, leaving 96.