Five percentage calculators in one
Percentages are everywhere: exam results, shop discounts, salary raises, tax and business growth. This percentage calculator puts the five most common calculations on one page. Every answer updates as you type, so you can try different numbers in seconds.
1. What is X% of Y?
Use this to find a share of a number, like a 15% tip or 20% tax. Formula: result = X ÷ 100 × Y. Example: 15% of 200 = 30.
2. X is what percent of Y?
Use this to see what part one number is of another. Formula: percent = X ÷ Y × 100. Example: 45 out of 60 = 75%.
3. Percentage increase or decrease
Use this for price changes, growth, weight loss or website traffic. Formula: change = (new − old) ÷ old × 100. Example: from 80 to 100 is a 25% increase. From 100 to 80 is a 20% decrease. Notice the two numbers are different, because the starting point changes.
4. Marks percentage
Students use this to turn exam marks into a percentage. Formula: percentage = obtained marks ÷ total marks × 100. Example: 845 out of 1100 = 76.82%.
The calculator also shows a grade band based on the common Pakistani board scale: A+ from 80%, A from 70%, B from 60%, C from 50%, D from 40% and E from 33%. Your school or board may use different bands, so always check the official rules.
5. Add or remove a percentage
Use this for discounts, sales tax, VAT and markups. Example: 1,500 with 20% added = 1,800. 1,500 with a 20% discount = 1,200.
Note that adding 20% and then removing 20% does not bring you back to the start: 1,800 minus 20% is 1,440. To remove tax that is already included in a price, divide by 1.2 instead.
Why percentages confuse people
Percentages always depend on the base number. A 50% drop followed by a 50% rise leaves you at 75% of where you started, not 100%. If you want to brush up on the basics, Math is Fun has a clear beginner's guide.
More free calculators
Planning a loan? The EMI Calculator shows your monthly payment and total interest. University students can use the GPA Calculator, and the Scientific Calculator handles everything else. See all calculators.
Percentage formulas you can remember
| Question | Formula | Example |
|---|---|---|
| What is X% of Y? | Y x X / 100 | 15% of 2,000 = 300 |
| X is what % of Y? | X / Y x 100 | 45 out of 60 = 75% |
| % change from A to B | (B - A) / A x 100 | 80 to 100 = +25% |
| Add X% to a price | price x (1 + X/100) | 1,000 + 18% = 1,180 |
| Remove X% from a price | price x (1 - X/100) | 1,000 - 20% = 800 |
| Find the original before X% was added | total / (1 + X/100) | 1,180 incl. 18% tax = 1,000 |
The last row is the one people get wrong most often. If a price including 18% tax is 1,180, the price before tax is not 1,180 minus 18%; it is 1,180 / 1.18 = 1,000.
Everyday examples
Shopping discounts. A shirt costs Rs 3,500 with 30 percent off. You pay 3,500 x 0.70 = Rs 2,450 and save Rs 1,050.
Salary increase. Your salary goes from Rs 80,000 to Rs 92,000. The increase is 12,000 / 80,000 x 100 = 15 percent.
Exam marks. You scored 912 out of 1,100. Your percentage is 912 / 1,100 x 100 = 82.91 percent.
Business profit margin. You sell a product for Rs 1,500 that costs you Rs 1,050. Profit is 450, so the margin on the selling price is 450 / 1,500 = 30 percent, while the markup on cost is 450 / 1,050 = 42.9 percent. Margin and markup are not the same thing.
Two common percentage traps
- Up and down are not equal. If a price rises 50 percent and then falls 50 percent, it does not return to the start. 100 becomes 150, then 75.
- Percent vs. percentage points. If an interest rate rises from 10 percent to 12 percent, it went up by 2 percentage points, which is a 20 percent increase.
About the marks grade bands
The marks calculator shows a grade band using the common Pakistani board scale (A+ for 80 percent and above, A for 70-79, B for 60-69, C for 50-59, D for 40-49, E for 33-39). Boards, universities and countries use different scales, so treat the grade as a guide and always check your own institution's rules.
Related calculators
For loans and instalments, use the EMI Calculator. For university grades, try the GPA Calculator. For anything more complex, the Scientific Calculator handles brackets, powers and roots. You can learn more about the maths behind percentages on Khan Academy.
Percentages in business and finance
Percentages appear in almost every business decision:
- Sales tax and GST. Adding tax to a price uses "add a percentage", while finding the price before tax uses the reverse calculation shown above.
- Discount campaigns. A "30 percent off" sale on a product with a 40 percent margin leaves very little profit, so calculate the final margin before announcing it.
- Growth reports. Monthly traffic, sales or followers are compared with "percentage change". A jump from 2,000 to 2,600 visitors is a 30 percent increase.
- Commission and fees. Payment gateways and marketplaces take a percentage of each sale; subtract it to see what you really earn.
- Interest. Loans and savings use annual percentage rates; for monthly loan payments, use the EMI Calculator.
Getting these numbers right helps you price products, set targets and compare offers honestly.
Frequently Asked Questions
How do I calculate a percentage of marks?
Divide the marks you got by the total marks and multiply by 100. For example, 450 ÷ 500 × 100 = 90%.
What is the difference between percent and percentage points?
If a rate goes from 10% to 12%, it rose by 2 percentage points, which is a 20% increase.
Can I use decimals and negative numbers?
Yes. All fields accept decimals, and negative numbers work for changes and losses.
Is it free?
Yes, free and private.
How do I calculate a discount of 25 percent?
Multiply the price by 0.75 to get the sale price, or by 0.25 to get the amount you save.
How do I find percentage increase in Excel?
Use =(new-old)/old and format the cell as a percentage. The calculator here gives the same answer instantly.
How do I calculate 18 percent tax on a price?
Multiply the price by 0.18 for the tax amount, or by 1.18 for the total including tax.
Last updated: October 25, 2026