Basic Math

Percentage Calculator

Three percentage questions in one tool: find a percentage of an amount, express one number as a percentage of another, or measure the percentage change between two values.

Inputsx% of y

What do you want to work out?XY

Step-by-step

waiting

Fill in the fields and press Solve. The full method will appear here, one numbered step at a time.

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Worked example

What is 15% of 80?

1.
A percentage is a fraction out of 100, so turn the percentage into a fraction.
```
15% = 15/100 = 0.15
```
2.
“Of” means multiply, so multiply that fraction by the amount.
```
3/20 × 80 = 12
```

Answer: 12

Note: Covers “X% of Y”, “X is what percent of Y” and percentage increase or decrease — not written word problems.

Use “Load worked example” above to run this in the solver.

Related formulas

The formulas this tool uses, each explained with symbols, conditions and its own example in the Formula Library.

Percentage of a quantityP% of Q = (P ÷ 100) × Q Percentage change% change = (new − original) ÷ original × 100