Percentage Calculator
History
Your results will appear here. Tap Use on any of them to carry it into the next calculation, in this calculator or another one. History is kept while this tab is open.
To calculate a percentage, divide the part by the whole and multiply by 100: 36 ÷ 240 × 100 = 15%. This percentage calculator also finds a percent of a number, percentage change and difference, and adds or subtracts a percent.
Percentage increase and decrease
These are two different questions, and each has its own tab.
To raise or lower a number by a percent, open +/− % and enter the number, pick + or −, then the percent. With + it works as a percentage increase calculator: 240 + 15% is 276. With − it's a percentage decrease or reduction calculator, and 240 − 15% is 204.
To calculate percentage increase or decrease between two numbers you already have, use Change. The result has a sign and a word: +50% with increase, −15% with decrease.
Percentage change
Percentage change always runs from the old value to the new one:
(new − old) ÷ old × 100
Put the old value in From and the new one in To. A positive result is growth, a negative one is a drop. From 50 to 75 is +50%. From 200 to 170 is −15%.
When the starting value is negative, the calculator divides by its absolute value, so a rise stays positive: −50 to −25 is +50%. Enter both numbers in the Change tab and press Calculate.
How it's calculated
The percentage formula is part ÷ whole × 100. That's how to calculate the percentage of two numbers. Under every result, the calculator writes it out with your numbers, rounded to two decimals: 1 out of 3 is 33.33%. For a share as a ratio, see the ratio calculator.
Percent of a number
part = percent ÷ 100 × whole: 15 ÷ 100 × 240 = 36
percent = part ÷ whole × 100: 36 ÷ 240 × 100 = 15%
whole = part ÷ (percent ÷ 100): 36 ÷ 0.15 = 240
To find a percentage of a number, divide the percent by 100 and multiply by the number. In the % of number tab, fill in any two of Percent, of and =, and the calculator finds the third.
Percentage increase formula
new = old × (1 + percent ÷ 100)
new = old × (1 − percent ÷ 100) for a decrease
For 15%, the multiplier is 1.15, so 240 × 1.15 = 276, the same line you'll see under the result in +/− %.
Percentage difference
Percentage difference compares two numbers without picking a starting point. The base is their average, so order doesn't matter and the answer has no sign:
|a − b| ÷ ((|a| + |b|) ÷ 2) × 100
For 200 and 170 the average is 185, so the difference is 30 ÷ 185 × 100 = 16.22%. Percentage change from 200 to 170 is −15%, because there the base is 200. You don't need a separate percent difference calculator: the Change tab shows percentage difference under every result.
Examples
Each row is one calculation. Use sends a result like 36 to the fraction calculator; to average several percentages, go to the average calculator.
| Tab | You enter | Result | Also shown | Formula line |
|---|---|---|---|---|
| % of number | Percent 15, of 240 | 36 | — | 0.15 × 240 = 36 |
| % of number | of 240, = 36 | 15% | — | 36 ÷ 240 × 100 = 15% |
| % of number | Percent 15, = 36 | 240 | — | 36 ÷ 0.15 = 240 |
| % of number | of 3, = 1 | 33.33% | — | 1 ÷ 3 × 100 = 33.33% |
| % of number | Percent 20, of 50 | 10 | — | 0.2 × 50 = 10 |
| % of number | After 15% of 240 = 36, change = to 48 | 20% | — | 48 ÷ 240 × 100 = 20% |
| Change | From 200, To 170 | −15% | decrease · Percentage difference: 16.22% | (170 − 200) ÷ 200 × 100 = −15% |
| Change | From 50, To 75 | +50% | increase · Percentage difference: 40% | (75 − 50) ÷ 50 × 100 = +50% |
| Change | From −50, To −25 | +50% | increase · Percentage difference: 66.67% | (−25 − (−50)) ÷ 50 × 100 = +50% |
| +/− % | 240, +, 15 | 276 | — | 240 × 1.15 = 276 |
| +/− % | 240, −, 15 | 204 | — | 240 × 0.85 = 204 |
FAQ
How do I calculate a percentage using a calculator?
Divide the part by the whole and multiply by 100. On any calculator, 36 ÷ 240 × 100 gives 15, so 36 is 15% of 240. Here, open % of number, enter 240 in of and 36 in =, and press Calculate.
What is the formula for percentage?
Percent = part ÷ whole × 100. The two reverse percent formulas, for the part and for the whole, are listed under Percent of a number above.
How do you calculate percentage increase?
Subtract the old value from the new one, divide by the old value and multiply by 100. From 50 to 75 that's (75 − 50) ÷ 50 × 100 = +50%. In the Change tab, enter 50 in From and 75 in To.
What is the difference between percentage change and percentage difference?
Percentage change goes from an old value to a new one and has a sign. Percentage difference measures the gap against the average of the two numbers and has none. For 200 and 170 the change is −15% and the difference is 16.22%; the Change tab shows both at once.
How do I find a percent of a percent?
Multiply them as decimals: 20% of 50% is 0.2 × 0.5 = 0.1, which is 10%. In the % of number tab, enter 20 in Percent and 50 in of, and you get 10. The calculator shows it without a % sign, but since 50 stood for 50%, the answer is 10%.