Percentage Calculator
The three percentage calculations everyone needs — find a percentage of a number, find what percent one number is of another, and find the percentage increase or decrease between two values.
How to use
- 1Use the first row for “what is X% of Y” — the answer updates as you type.
- 2Use the second row to find what percentage one number is of another.
- 3Use the third row for the percentage increase or decrease between two values.
Frequently Asked Questions
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. For example 15% of 200 = 200 × 15 ÷ 100 = 30.
How do I work out what percent one number is of another?
Divide the part by the whole and multiply by 100. For example 30 out of 200 = 30 ÷ 200 × 100 = 15%.
How is percentage change calculated?
Subtract the old value from the new value, divide by the old value, and multiply by 100. Going from 100 to 125 is (125 − 100) ÷ 100 × 100 = +25%.
How do I calculate exam marks percentage?
Use the second row: your marks obtained 'is what percent of' the total marks. For example 432 out of 500 = 86.4%.
How do I add or remove a percentage from a price?
To add 18%, multiply by 1.18. To remove it, divide by 1.18 — do not subtract 18%, which is the most common mistake. For GST specifically, the GST calculator does both directions for you.
Why is a 50% fall not undone by a 50% rise?
Because each percentage is taken from a different base. A ₹100 investment that drops 50% is worth ₹50; a 50% rise on ₹50 takes you back to ₹75, not ₹100. Getting back to ₹100 needs a 100% rise.