Percentage Calculator
This percentage calculator answers the questions people ask most: what is X% of Y, what percent is one number of another, and how much did a value increase or decrease? Enter your numbers and get an instant answer without having to remember the formula.
Common Percentage Calculations
1. What is X% of Y?
Multiply Y by X and divide by 100. Example: 20% of 150 = 150 × 20 ÷ 100 = 30. This is the calculation behind tips, commissions and taxes.
2. X is what percent of Y?
Divide X by Y and multiply by 100. Example: 45 out of 60 = 45 ÷ 60 × 100 = 75%. Useful for test scores, progress toward a goal or a share of a budget.
3. Percentage increase or decrease
Subtract the old value from the new value, divide by the old value and multiply by 100. Example: a price rising from 80 to 100 is (100 − 80) ÷ 80 × 100 = 25% increase. A negative result means a decrease.
Try another free calculator
4. Adding or subtracting a percentage
To add 15% to 200, multiply 200 by 1.15 to get 230. To subtract 15%, multiply by 0.85 to get 170. This shortcut is how prices with tax or after a discount are calculated. For shopping, the discount calculator does this automatically and shows your savings.
Percent Change vs. Percentage Points
These two ideas are often confused. If an interest rate moves from 4% to 5%, it has risen by one percentage point, but the percent change is 25%, because 1 is a quarter of 4. News reports, financial statements and survey results use both, so it is worth checking which one is meant before drawing conclusions.
Why Percentages Can Be Tricky
A 50% increase followed by a 50% decrease does not bring you back to where you started. Starting at 100, a 50% rise gives 150, and a 50% drop from 150 gives 75. That is because each percentage is applied to a different base. Whenever you chain percentages together, calculate each step from the new value rather than the original.
Another common slip is dividing by the wrong number. In percent change, always divide by the starting value. In "what percent of" questions, divide by the whole, not the part.
Where Percentages Show Up Every Day
Percentages are everywhere: sales and coupons, tips, grades, interest rates, pay rises, nutrition labels and statistics. A reliable percentage calculator helps you check numbers quickly and make better decisions. If you want to see how a raise affects your pay over a year, try the salary calculator as well.
Frequently Asked Questions
How do I calculate X percent of a number?
Multiply the number by the percentage, then divide by 100. For example, 12% of 250 is 250 × 12 ÷ 100 = 30. You can also convert the percentage to a decimal first, so 12% becomes 0.12, and multiply: 250 × 0.12 = 30.
How do I calculate percentage increase or decrease?
Subtract the original value from the new value, divide the difference by the original value and multiply by 100. If the result is positive it is an increase, and if negative it is a decrease. For example, going from 50 to 40 is a 20% decrease.
How do I find what percent one number is of another?
Divide the part by the whole and multiply by 100. For example, 18 out of 24 is 18 ÷ 24 × 100 = 75%. This works for exam scores, survey results, completed tasks and any situation where you compare a part to a total.
What is the formula for percent change?
Percent change = (new value − old value) ÷ old value × 100. Always divide by the old, or starting, value. For example, a change from 200 to 260 is (260 − 200) ÷ 200 × 100, which equals a 30% increase.
How do I add or subtract a percentage from a number?
To add a percentage, multiply by 1 plus the decimal, so adding 10% to 90 is 90 × 1.10 = 99. To subtract, multiply by 1 minus the decimal, so 90 × 0.90 = 81. This is the quickest way to apply tax, markups or discounts.