- Percent of base
- Base plus percent
- Base minus percent
Math utility
Percentage Calculator
Work out discounts, markups, completion rates, conversion rates, and growth from a few common percentage formulas.
Percent of a number
Multiply the base by the percent divided by 100. For example, 15% of 200 is 200 x 0.15 = 30.
Percent change
Subtract the start value from the end value, divide by the start value, then multiply by 100.
Part of total
Divide the part by the total and multiply by 100 to estimate share, completion, or conversion rate.
Percentage FAQ
Why can percent change be negative?
A negative result means the end value is lower than the start value. It represents a decrease.
Why is zero blocked as a starting value?
Percent change divides by the start value, so zero would make the formula undefined.
Is adding 20% then subtracting 20% the same?
No. The second percentage uses a different base. Adding 20% to 100 gives 120, then subtracting 20% from 120 gives 96.