Percentage Calculator — Percent, Increase & Discount
A percentage calculator works out percentages in seconds — what percent one number is of another, a percentage of a number, or how much a value has increased or decreased.
How it works
- Choose a mode: “What is X% of Y?”, “X is what % of Y?” or “Percentage change”.
- Enter your two numbers and the answer appears instantly.
- Use the discount mode to find sale prices and savings.
Formula
Worked example
25% of 200 is 50. And 25 is 12.5% of 200 (25 ÷ 200 × 100). If a price rises from $80 to $100, the increase is 25% ((100 − 80) ÷ 80 × 100).
Frequently asked questions
How do I calculate a percentage increase?
Subtract the old value from the new value, divide by the old value, then multiply by 100. For example, $80 to $100 is (20 ÷ 80) × 100 = 25%.
What percentage is 25 of 200?
25 is 12.5% of 200. Divide 25 by 200 to get 0.125, then multiply by 100.
How do I find a percent of a number?
Multiply the number by the percentage and divide by 100. For example, 25% of 200 is 200 × 25 ÷ 100 = 50.
How do I calculate a discount percentage?
Subtract the sale price from the original price, divide by the original price and multiply by 100. A $100 item on sale for $75 is a 25% discount.
What is the percentage change formula?
Percentage change = ((new value − old value) ÷ old value) × 100. A positive answer is an increase; a negative answer is a decrease.
How do I calculate a percentage decrease?
Use the same change formula. If a value falls from 200 to 150, the change is (150 − 200) ÷ 200 × 100 = −25%, so a 25% decrease.