Percentage calculator
Two numbers in, every percentage relationship between them out.
Every question below is answered from these two numbers at once — there is nothing to pick and nothing to submit.
- What is 15% of 200?30
- 15 is what percent of 200?7.5%
- What is the change from 15 to 200?1,233.333333%
- What is 200 increased by 15%?230
- What is 200 decreased by 15%?170
- What is the percentage difference between 15 and 200?172.0930233%
Percent change and percentage difference are not the same
Going from 10 to 20 is a 100% increase; going back from 20 to 10 is a 50% decrease. Same two numbers, same gap, two different figures — because percent change is measured against wherever you started. That asymmetry is real and it is why a rise of 50% followed by a fall of 50% does not return you to where you began.
Percentage difference avoids the question by measuring against the average of the two instead, so it gives one answer whichever way round you ask: 10 and 20 differ by 66.67%. Both are on this page because both get asked, and picking the wrong one is the most common way a correct calculation ends up reported wrongly.
When there is no answer
Two of these questions have no answer when a value is zero. Nothing is a percentage of zero, and a change from zero has no percentage either — any increase from nothing is infinitely more than nothing. Those cards show a dash and say why, rather than printing the ∞ or NaN that a division would produce.
