Work out what a percentage of a number is, or how much one value has changed as a percentage — both instantly, no manual maths.
Find X% of a number, or work out the percentage change between two values.
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Result
Percentage change is calculated relative to the original value — a rise from 100 to 150 is 50% up, but a fall back from 150 to 100 is a 33.3% drop, not 50%.
A percentage is a fraction out of 100. Finding "X% of a number" means multiplying the number by X and dividing by 100. Percentage change compares a new value to an original one — and because it's always measured against the original, increases and decreases of the same absolute amount rarely produce mirror-image percentages.
Find a percentage of a number, or the percentage change between two values.
A percentage and a value, or an original and a new value.
The calculated amount or percentage, worked out instantly.
The percentage formulas
X% of number = (X ÷ 100) × number
Percentage change = [(new value − original value) ÷ original value] × 100
A positive result means an increase; a negative result means a decrease.
A worked example
Finding 20% of 500, then checking the change from 500 to 600:
| 20% of 500 | 100 |
| Original value | 500 |
| New value | 600 |
| Difference | 100 |
| Percentage change | +20% |
Now reverse it: going from 600 back down to 500 is a −16.7% change, not −20% — because the base value used for the percentage is different each direction.
Common percentage uses
%
Discounts and markups
Δ%
Salary hikes, growth rates
%
Exam scores, grading
Δ%
Investment returns
Because each percentage is calculated on a different base. A 20% increase on 100 gives 120, but a 20% decrease is then calculated on 120, not the original 100 — giving 96, not 100.
Divide the first number by the second, then multiply by 100. For example, 40 out of 200 is (40 ÷ 200) × 100 = 20%.
A percentage point is a plain difference between two percentages, while a percentage change is relative. Going from 20% to 25% is a rise of 5 percentage points, but a 25% relative increase in the percentage itself.
Yes — if a value more than doubles, the percentage increase exceeds 100%. For example, going from 50 to 150 is a 200% increase.
This calculator pairs well with our discount calculator for a full pricing breakdown.