Percentage Calculator

To find the percent of a number manually, multiply the number by the percentage fraction (percentage divided by 100). For example, to calculate 20% of 150: (20 / 105) * 150 = 30. Alternatively, paste your numbers into our percentage calculator online to get the exact value instantly.

To calculate percentage change: subtract the old value from the new value, divide the result by the absolute value of the old value, and then multiply by 100.

Formula: ((New Value - Old Value) / Old Value) * 100.

If the result is positive, it represents an increase; if negative, it is a percentage decrease.

Finding what is X percent of Y translates to the algebraic expression: Value = (X / 100) * Y. For instance, to calculate 15% of $80, compute (15 / 100) * 80 = 12. Our percentage calculator handles this formula as well as reverse percentage calculations automatically.

To find what percentage number X is of number Y, divide X by Y and multiply the quotient by 100.

Formula: Percentage = (X / Y) * 100.

For example, if you scored 45 out of 60 on a test, your percentage is (45 / 60) * 100 = 75%.

The core percentage formula is: Part / Whole = Percentage / 100. By rearranging this basic ratio, you can solve for any of the three variables:

1. Find percentage: (Part / Whole) * 100
2. Find part: (Percentage / 100) * Whole
3. Find whole: Part / (Percentage / 100)