Three questions, one page
Most percentage problems are one of three: what percent of Y is X, what is X% of Y, and how much did something change. They use the same arithmetic but people mix up which number goes on the bottom, so each has its own tab here.
Percent and percentage point are not the same
If a rate goes from 4% to 5%, that is a rise of one percentage point but of 25 percent. Both statements are true and they describe the same change, which is exactly why headlines are so easy to misread.
While you’re here — claim a crypto exchange bonus
More calculators
Frequently asked questions
Q. Why is a 50% rise not undone by a 50% fall?
Because the base changes. 100 rises by 50% to 150; 150 falls by 50% to 75, not back to 100. To undo a 50% rise you need a 33.3% fall.
Q. How is percentage change calculated?
(new − old) ÷ old × 100. The old value is always the denominator, which is why swapping the two gives a different number.
Q. What if the starting value is zero?
Percentage change is undefined — you cannot divide by zero. Growth from nothing has to be described in absolute terms instead.