Use the Percentage Calculator in three steps
Choose the matching question
Use percentage of, share of total, or percentage change.
Enter the numbers
Type whole numbers, decimals, or negative values when appropriate.
Read the live result
The answer updates without a submit button.
Percentage change uses the original value
Change is calculated as the difference divided by the absolute original value, then multiplied by 100. A positive answer is an increase and a negative answer is a decrease.
Zero needs special handling
A share cannot be divided by a total of zero, and percentage change from zero is undefined. The calculator shows a dash instead of a misleading result.
Percentage Calculator FAQ
How do I calculate 20% of a price?＋
Enter 20 in the first box and the price in the second. The result is the percentage amount, not the discounted final price.
How do I find a test-score percentage?＋
Use the second calculator: points earned is the part and total available points is the whole.
How is percentage increase calculated?＋
Subtract the old value from the new value, divide by the absolute old value, and multiply by 100.
Can I enter decimals?＋
Yes. All three calculators accept decimal values.
Why does the result show a dash?＋
The selected calculation would require division by zero or one of the entries is not a valid number.
Can percentage change be negative?＋
Yes. A negative result indicates a decrease from the original value.