Percentage Calculator
Find a percentage of a number, what percent one number is of another, and percentage change.
Percentage formulas
To find a percentage of a number, multiply the number by the percentage and divide by 100. To find what percent A is of B, divide A by B and multiply by 100. Percentage change equals (new − old) ÷ old × 100.
Where you will use it
Discounts, tips, tax, grades, interest and price changes all use percentages. Enter any two numbers and read all the common answers at once.
Worked example
Last reviewed November 2026. Formulas are standard and shown in the sections above; results are estimates.
Tips and common mistakes
- Percent change is not the same as percentage points.
- A 50% rise then a 50% fall does not return you to the start.
- Use the discount calculator for sale prices.
Frequently asked questions
How do I calculate percentage change?
Subtract the old value from the new value, divide by the old value and multiply by 100.
What is the difference between % and percentage points?
Going from 10% to 12% is a 2 percentage point rise, but a 20% increase.
Can I use negative numbers?
Yes, results follow the same formulas.
Money guides for this topic
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Open calculator →Results are estimates and not financial advice.