Six percentage calculators in one – with the formula shown for every answer.
What is the Percentage Calculator?
Percentages are everywhere – exam marks, sale discounts, salary raises, taxes, interest rates and business growth. This percentage calculator solves the six most common percentage questions in one place and shows the formula for each answer, so you can also learn how it works.
Use it to find 15% of 200, see what percent 30 is of 120, measure the percentage increase from 80 to 100, add or remove a percentage, or compare two numbers with the percentage difference.
How to use the Percentage Calculator
- Pick the calculation you need.
- Type your two numbers – the answer updates instantly.
- Read the formula below the answer to double-check.
Percentage formulas
| Question | Formula | Example |
|---|---|---|
| X% of Y | X ÷ 100 × Y | 15% of 200 = 30 |
| X is what % of Y | X ÷ Y × 100 | 30 of 120 = 25% |
| % change | (new − old) ÷ old × 100 | 80 → 100 = +25% |
| Add X% | Y × (1 + X/100) | 500 + 18% = 590 |
| Subtract X% | Y × (1 − X/100) | 2,500 − 20% = 2,000 |
Percentage change vs percentage difference
Use percentage change when there is a clear “before” and “after” (price went from 80 to 100). Use percentage difference when comparing two values with no direction, like two shop prices – it divides by their average.
Frequently asked questions
How do I calculate a percentage of marks?
Divide obtained marks by total marks and multiply by 100. Our Marks Percentage Calculator does this and shows your grade.
Is a 50% increase then a 50% decrease the same number?
No. 100 + 50% = 150, then 150 − 50% = 75.
How do I reverse a percentage?
To find the original price before a 20% discount, divide the sale price by 0.8.
Can I use decimals?
Yes, every box accepts decimals and negative numbers.
This percentage calculator is 100% free, needs no signup and works on phones, tablets and computers. Your data is processed in your browser and never uploaded.
Last updated: · By NodifyTech