Percentage Calculator

Enter two numbers and see five common percentage answers at once: a percentage of a value, one number as a percentage of another, the percentage change between them, and an increase or decrease.

How to use it

  1. Enter Value A (the percentage or first number) and Value B.
  2. Read all five results at once.
  3. Change either value to update every result.

Frequently asked questions

How do I work out percentage change?

(new − old) ÷ |old| × 100. From 20 to 150 that is 650%.

How do I add a percentage to a number?

Multiply by 1 plus the percentage as a decimal. Adding 20% to 150 is 150 × 1.2 = 180.

What if the old value is zero?

Percentage change from zero is undefined, so the calculator shows a dash.

This is an estimate for general information, not tax, legal or financial advice.