Percentage Calculator
Enter a value and a percentage below to instantly see the result — useful for exam marks, discounts, tips, and everyday financial figures.
The formula
To find a percentage of a value, multiply the value by the percentage and divide by 100:
result = (value × percent) ÷ 100
Worked example
A shop lists a jacket at 1,800 and offers a 15% loyalty discount. 15% of 1,800 is (1,800 × 15) ÷ 100 = 270. Subtract that from the price and the jacket costs 1,530.
Finding a percentage the other way round
If you know two numbers and want to know what percentage one is of the other, divide the part by the whole and multiply by 100: (part ÷ whole) × 100. For instance, if you scored 42 out of 60 on a test, (42 ÷ 60) × 100 = 70%.
Where this is useful
- Working out exam or assignment scores
- Checking sale prices and markdowns
- Calculating tips, service charges, or commission
- Comparing year-on-year growth or decline in a figure
More worked examples
- 12.5% of 80 is (80 × 12.5) ÷ 100 = 10.00.
- 7.5% of 19.99 is 1.49925, which the tool shows as 1.50 because it displays two decimal places.
- 150% of 40 is 60.00. A percentage above 100 is fine, and 0% of any value is 0.00.
- Negative values are accepted as they are: 15% of −200 is −30.00.
Adding or removing a percentage
The result is the percentage part only. To add 15% to 1,800, calculate 15% of 1,800 (270) and add it to get 2,070. To take it off, subtract it to get 1,530. You can also multiply by 1.15 or 0.85 for the same totals.
Percentage change between two numbers
For the change from an old value to a new one, work out (new − old) ÷ old × 100. From 80 to 100 is +25%, but from 100 back to 80 is −20%, because each change is measured against a different starting value. This calculator does not do that step for you, but it can check the result: 25% of 80 is 20.00.
Rounding, errors and limits
- The answer updates as you type and is rounded to two decimal places only for display. The values you type are used as they are.
- If either box is empty you see "Please enter both a value and a percentage."
- A product that overflows, such as 200% of 1e308, shows "Those values are too large to calculate. Please enter smaller numbers."
Guide
- GST Calculations Explained: Inclusive vs Exclusive — Adding and removing GST correctly, the common mistake with inclusive prices, and when the tax splits into CGST and SGST versus IGST.
Frequently asked questions
Can a percentage be more than 100?
Yes. Percentages above 100 are common when describing growth, markups, or increases — for example, a value that doubles has grown by 100%, and one that triples has grown by 200%.
How do I find what percentage one number is of another?
Divide the smaller (part) number by the larger (whole) number, then multiply by 100. For example, 30 out of 150 is (30 ÷ 150) × 100 = 20%.
Why do my exam marks and this calculator give slightly different results?
Some institutions round intermediate steps or apply grace marks before calculating the final percentage. This tool multiplies the exact numbers you type and rounds only the final answer to two decimal places, so check your institution's specific method if the figures must match exactly.
Does the calculator round the result?
Only the final answer, and only for display: it is shown to two decimal places. The calculation itself uses the exact numbers you typed, so 7.5% of 19.99, which is 1.49925, is shown as 1.50.
Can I use negative numbers or percentages over 100?
Yes to both. 15% of −200 is −30.00, and 150% of 40 is 60.00. There is no upper limit on the percentage, other than numbers so large that the result overflows.
How do I add a percentage to a number with this tool?
Find the percentage part first, then add it yourself. For 15% on 1,800, the tool gives 270.00 and the new total is 1,800 + 270 = 2,070. To remove it, subtract 270 to get 1,530.