How to use the Percentage Calculator
- Choose the question you want answered.
- Enter the two numbers.
- Read the answer and the formula used.
The three percentage formulas
| Question | Formula | Example |
|---|---|---|
| What is 18% of 2,500? | 2,500 × 18 ÷ 100 | 450 |
| 450 is what % of 2,500? | 450 ÷ 2,500 × 100 | 18% |
| 2,000 → 2,500 is what % change? | (2,500 − 2,000) ÷ 2,000 × 100 | 25% increase |
Note
A rise and a fall of the same percentage don't cancel out: +25% then −25% on 2,000 gives 1,875, not 2,000. The second percentage is taken on a bigger number.
Worked example
Marks: 432 out of 500
- 432 ÷ 500 × 100
86.4%
Frequently asked questions
How do I calculate percentage of marks?
Divide marks obtained by total marks and multiply by 100. 432 out of 500 is 86.4%.
How do I add 18% to a price?
Multiply by 1.18. For GST on a price, the GST Calculator also splits the tax into CGST and SGST.