Calculators & Converters
Percentage Calculator
Solve common percentage questions without rearranging a formula yourself. Choose the mode that matches your problem: percentage of a number, increase or decrease, reverse percentage, difference, ratio or markup.
Choose a percentage calculation
Percentage Calculator
Choose a calculation type, enter your values, and see the result and formula immediately.
Calculation
Result
Formula used
(15 ÷ 100) × 500 = 75
Explanation
15% of 500 is 75.
Your calculation is processed in your browser and is not stored by this tool.
The values you enter stay in browser memory. Results use the selected percentage mode and are rounded for display.
How to use the percentage calculator
- 1
Choose the calculation that matches the wording of your question.
- 2
Enter the values in the labelled fields. For percentage change, put the earlier value first and the new value second.
- 3
Run the calculation and read the result together with the displayed formula.
- 4
Check whether you need a percent, a percentage-point difference or a money amount.
- 5
Change the values to compare another discount, mark, price or growth scenario.
Common percentage formulas
X% of Y: multiply Y by X ÷ 100. Percentage change: subtract the original value from the new value, divide by the original value, then multiply by 100. Reverse percentage: rearrange the same relationship to recover the unknown original or whole value.
18% of 250: 250 × 18 ÷ 100 = 45.
Increase from 80 to 100: (100 − 80) ÷ 80 × 100 = 25%.
Percentage change versus percentage points
These are not the same. If a rate moves from 20% to 25%, it rises by 5 percentage points. Relative to the original 20%, the increase is 25%. Stating the right measure prevents a result from sounding larger or smaller than it is.
Marks, discounts, money and markup
For marks, divide the score by the total possible marks and multiply by 100. For a discount, multiply the original price by the discount rate to find the saving, then subtract it from the original price. Markup compares profit with cost, while profit margin compares profit with selling price; use the dedicated Profit Margin Calculator when that distinction matters.
Important notes
- A percentage change cannot use zero as the starting value because division by zero is undefined.
- Rounding can create a small difference when you reverse a displayed percentage.
- For money, keep more decimal precision during the calculation and round only the final amount according to the relevant rule.
- CGPA-to-percentage conversions are institution-specific; do not assume one universal formula.
Related tools
Percentage Calculator FAQ
How do I find a percentage of a number?
Multiply the number by the percentage divided by 100. For example, 18% of 250 is 250 × 0.18 = 45.
How do I calculate percentage increase or decrease?
Subtract the original value from the new value, divide by the original value and multiply by 100. A negative result is a decrease.
What is the difference between percentage change and percentage difference?
Percentage change uses an original value as the base. Percentage difference compares two values symmetrically, usually using their average as the base.
How do I find the original number from a percentage?
Use a reverse-percentage mode. For example, if 45 is 18% of the whole, divide 45 by 0.18 to get 250.
Can I use this as a marks percentage calculator?
Yes. Divide marks earned by total marks and multiply by 100. Any grade or CGPA conversion rule must come from the relevant institution.
Why is my answer slightly different?
Different tools may round inputs or results at different stages. Compare the same formula and keep enough decimal places before rounding the final value.
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