Calculators
Percentage calculator
Most percentage confusion comes from asking three different questions with the same word. Each is answered separately here, so you always know which one you calculated.
What is X% of Y
X is what percent of Y
Percent change
How to use it
- Top row: what is 25% of 200?
- Middle row: 30 is what percent of 120?
- Bottom row: the change from 80 to 100, as a percentage.
- Every result updates as you type.
A percentage always has a base
“Up 20%” means nothing until you know what it is 20% of. A 20% rise followed by a 20% fall does not return to where it started: 100 becomes 120, then 96. This asymmetry is why losses hurt more than equivalent gains feel good, and why “we recovered 20%” after a 20% drop still leaves you 4% below the line.
Points, not percent
Moving from 4% to 5% is a rise of one percentage point, but a 25% increase. In interest rates, polling and medical risk that distinction changes the meaning entirely. A “50% increase in risk” sounds alarming until you learn it went from 2 in 10,000 to 3 in 10,000 — a single extra case in ten thousand people.
Three questions that all sound like "percent"
What is 20% of 250 (50). What percent is 50 of 250 (20%). From 250 to 300 is a 20% increase. These are different operations, and the expensive mistake is applying the wrong one to a discount: 25% off then another 20% off is not 45% off, it is 40% off, because the second discount applies to the reduced price.
Reverse percentage trips up almost everyone. If a price after 20% off is 80, the original is 100 — not 96. Divide by 0.8, do not add 20%. The same error appears in VAT calculations, where the tax is a fraction of the net figure, not of the gross.
Frequently asked questions
Why does a 50% drop need a 100% rise to recover?
Because the base changes. Losing half of 100 leaves 50; getting back to 100 from 50 is a 100% increase of the smaller number. Percentages are always relative to where you started.
How is percentage change calculated?
The difference divided by the original, times 100. It is divided by the absolute value of the starting number so the sign of the result reflects direction, not the sign of the input.
What is the difference between percent and percentage point?
Going from 10% to 11% is a rise of one percentage point but a 10% increase. Newspapers mix these up constantly; the distinction matters in finance and polling.
Can I use it for discounts?
Yes — enter the price and the discount percent in the first row. For a full breakdown of tax and final price, the loan calculator's arithmetic is closer to what you need.
How do I find the original price after a discount?
Divide by (1 − discount). A 20% discount means the price is 80% of the original, so 80 ÷ 0.8 = 100. Adding 20% instead gives the wrong 96.
Is a 50% increase cancelled by a 50% decrease?
No. 100 → 150 → 75. Percentage changes are relative to different bases, which is why losses need a larger gain to recover.