Percentage Calculator
Find a percentage of a number, work out percent change, convert between percent, decimal and fraction, or calculate your test marks percentage. Results update as you type.
What is X% of Y?
Example: what is 15% of 200?
X is what percent of Y?
Example: 18 is what percent of 60?
X is Y% of what number?
Example: 25 is 20% of what?
Percentage increase / decrease
How much did a value change, in percent?
Increase or decrease a number by %
Add or subtract a percentage from a number.
Percentage difference
Compare two values with neither as the starting point.
Marks percentage calculator
Enter marks for each subject to get your overall percentage and letter grade.
| Subject | Marks obtained | Total marks |
|---|
Letter grades use the flat 10-point scale: 90-100 = A, 80-89 = B, 70-79 = C, 60-69 = D, below 60 = F. Check your school’s own scale for official results.
Percent, decimal and fraction converter
Type in any one box and the other two update.
How to calculate a percentage
A percentage is a number expressed as a fraction of 100. To find what percent one number is of another, divide the part by the whole and multiply by 100.
For example, if a student gets 22 questions right out of 25: 22 ÷ 25 × 100 = 88%.
Percentage formulas
| What you want | Formula |
|---|---|
| X% of Y | (X ÷ 100) × Y |
| X is what % of Y | (X ÷ Y) × 100 |
| X is Y% of what | X ÷ (Y ÷ 100) |
| Percent change | (New − Old) ÷ |Old| × 100 |
| Percent difference | |A − B| ÷ ((A + B) ÷ 2) × 100 |
| Increase by P% | Number × (1 + P ÷ 100) |
| Decrease by P% | Number × (1 − P ÷ 100) |
Worked examples
| Question | Working | Answer |
|---|---|---|
| What is 15% of 200? | 15 ÷ 100 × 200 | 30 |
| 18 is what % of 60? | 18 ÷ 60 × 100 | 30% |
| 25 is 20% of what? | 25 ÷ 0.20 | 125 |
| Change from 80 to 100 | (100 − 80) ÷ 80 × 100 | +25% |
| Difference between 10 and 6 | 4 ÷ 8 × 100 | 50% |
| 500 increased by 10% | 500 × 1.10 | 550 |
| Test score 22 out of 25 | 22 ÷ 25 × 100 | 88% |
How to use this calculator
- Pick the calculator that matches your question.
- Type your numbers into the boxes.
- Read the answer and the short working shown under it.
Frequently asked questions
How do I calculate a percentage of a number?
Divide the percentage by 100, then multiply by the number. For 20% of 150: 20 ÷ 100 × 150 = 30.
How do I find my marks percentage?
Add up the marks you obtained, add up the total marks, then divide obtained by total and multiply by 100. The marks calculator above does this for any number of subjects.
What is the difference between percent change and percent difference?
Percent change compares a new value to an old starting value. Percent difference compares two values with neither as the starting point, using their average as the base.
Can a percentage be more than 100%?
Yes. 125% means one and a quarter times the base value. It is common in growth and price-change calculations.
Does QuickGrade store what I type?
No. Everything runs in your browser and nothing is uploaded or shared.