How to Calculate Percentages
A plain-English guide to the three common percentage calculations, with worked examples and links to the free finance calculators on Nexora Tools.
Browse all tools →The three percentage questions you actually need
Almost every percentage problem is one of three shapes. What is X% of Y, for example 20% of 500. X is what percent of Y, for example 45 out of 60. And X is Y% of what, for example 90 is 30% of some total. Once you can spot which shape you are dealing with, the arithmetic is short.
Worked examples
What is 20% of 500? Multiply 500 by 20 and divide by 100, which gives 100. What percent is 45 of 60? Divide 45 by 60 to get 0.75, then multiply by 100 for 75%. 90 is 30% of what number? Divide 90 by 30 and multiply by 100, which gives 300. For a percentage increase from 250 to 300, take the difference of 50, divide by the original 250, and multiply by 100 for a 20% rise.
Discounts and tax in everyday use
A 25% discount on 1,200 removes 300, leaving 900. Working backwards from a sale price, if an item costs 900 after 25% off, divide 900 by 0.75 to recover the original 1,200. Indian GST works the same way: to strip 18% GST from a total of 1,180, divide by 1.18 to get the base amount of about 1,000.
Calculators available on this site
Nexora Tools does not have a dedicated percentage calculator, so the examples above are worked by hand. It does have related finance calculators: a GST calculator for adding or removing GST, an EMI calculator for loan instalments, an SIP calculator for investment growth, and an FD/RD calculator for deposit returns. All of them are free and need no account.
Frequently asked questions
- What is the formula for a percentage of a number?
- Multiply the number by the percentage and divide by 100. For 15% of 240, calculate 240 times 15 divided by 100, which is 36.
- How do I work out a percentage increase or decrease?
- Divide the change by the original value and multiply by 100. Going from 80 to 100 is a change of 20, and 20 divided by 80 times 100 is a 25% increase.
- Is there a percentage calculator on Nexora Tools?
- Not at the moment. This page explains the calculations instead, and links to the GST, EMI, SIP and FD/RD calculators that are available.
- How do I remove GST from a total?
- Divide the total by 1 plus the GST rate as a decimal. For 18% GST, divide the total by 1.18 to get the pre-GST amount. The GST calculator on this site does it for you.