Percentage Calculator
Quickly calculate percentages, percentage change, and percentage of a total.
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How to use this calculator
Multiply your number by the percentage and divide by 100.
- 1
Enter the number you want to find a percentage of.
- 2
Enter the percentage you want to calculate.
- 3
The result appears instantly below the inputs.
Frequently asked questions
How do I calculate 20% of a number?
Enter the number in the first field and 20 in the percentage field. The calculator multiplies the number by 20 and divides by 100.
How do I find what percentage one number is of another?
Divide the part by the whole and multiply by 100. For example, 30 out of 200 is (30 ÷ 200) × 100 = 15%.
What is percentage change?
Percentage change = ((New Value − Old Value) ÷ Old Value) × 100. A positive result is an increase; negative is a decrease.
What is a percentage?
How percentages work
A percentage is a way of expressing a number as a fraction of 100. The word comes from the Latin "per centum," meaning "by the hundred." Percentages are used everywhere — from bank interest rates and tax calculations to discounts and exam scores.
Common percentage formulas
To find X% of Y: multiply Y by X and divide by 100. To find what percentage X is of Y: divide X by Y and multiply by 100. To calculate percentage change: subtract the old value from the new, divide by the old value, and multiply by 100.
Practical uses
Percentage calculators are used by students checking grades, shoppers comparing discounts, investors tracking portfolio returns, and businesses measuring growth. Understanding percentages is one of the most universally useful mathematical skills.
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