Percentage Calculator
Three modes in one: X percent of Y, X as a percent of Y, and percent change. Pick a mode and go.
Switch modes with the tabs above. Everything updates live as you type.
The three percent calculator questions
Almost every percentage problem is one of three questions, and this percent calculator handles all three: First: what is X percent of Y, the discount and tip question. Second: X is what percent of Y, the ratio question, like what share of the budget went to marketing. Third: what is the percent change from X to Y, the growth question, like how much a price or a salary moved.
People mix up the second and third constantly. A ratio compares a part to a whole at one moment. A change compares two moments in time. Going from 200 to 250 visitors is a 25 percent increase (change), while 50 out of 250 visitors is 20 percent (ratio). Different questions, different answers, and this calculator keeps them separate with the mode tabs.
Percent vs percentage points
Here is the trap worth knowing. If support for something rises from 20 percent to 25 percent, that is a 5 percentage point increase, but a 25 percent relative increase. News headlines sometimes blur the two, and the difference matters: one sounds small, the other sounds big, and both describe the same move.
When you report a change, say which one you mean. In business writing, percentage points are usually the clearer choice for comparing rates, while percent change is better for describing growth of a single number over time.
Quick mental math tricks
For 10 percent, move the decimal one place left. For 5 percent, halve the 10 percent figure. For 15 percent, add the two together. These three moves cover most everyday percentages: tips, discounts and taxes. The calculator is here for the exact numbers, but the tricks are worth knowing for quick estimates.
Frequently asked questions
How do I calculate X percent of Y?
Divide X by 100 and multiply by Y. For example, 20 percent of 150 is 0.2 times 150, which is 30. Choose the first mode in the calculator and it does this for you.
How do I find what percent X is of Y?
Divide X by Y and multiply by 100. For example, 30 as a percent of 150 is 30 divided by 150 times 100, which is 20 percent.
How is percent change calculated?
Subtract the old value from the new value, divide by the old value, and multiply by 100. A price rising from 50 to 60 is a 20 percent increase.
What is the difference between percent and percentage points?
Percentage points measure the plain difference between two percents. Going from 20 percent to 25 percent is a 5 percentage point rise, but a 25 percent relative increase.
Is my data stored anywhere?
No. The calculation runs entirely in your browser and your numbers are never uploaded, saved or shared.
How do I calculate percent increase?
Subtract the old value from the new value, divide by the old value, and multiply by 100. For example, going from 50 to 75 is a 50 percent increase. The percent change calculator above does it instantly.
What is the difference between percent change and percentage points?
Percent change is relative: going from 10 percent to 15 percent is a 50 percent increase. Percentage points are absolute: that same move is 5 percentage points. Mixing them up is one of the most common math mistakes in news headlines.