Percentage Calculator (Three Ways)
Most everyday percentage questions fall into three shapes, and this page puts all three side by side. The first computes “X percent of Y”, for example 20 percent of 250,000. The second says what percentage X is of Y, useful for seeing how much one item is of a total. The third gives the percentage change from one value to another and marks it with an up or down arrow. All three recalculate on every keystroke, numbers are shown with thousands separators, and results are rounded to four decimals. A zero or empty divisor shows a dash rather than a meaningless result.
This tool runs entirely in your browser. No data is sent to any server.
How to use it
- 1
For “percent of”, put the percentage and the base number in the first row.
- 2
For “what percentage”, enter the part and the total in the second row.
- 3
For “percent change”, fill in the original and the new value in the third row; the arrow shows the direction.
Frequently asked questions
How is percentage change different from percentage points?
Percentage change is measured against the original value: 100 to 130 is a 30 percent increase. Percentage points are the plain difference between two percentages, a rate moving from 10 to 13 percent rose 3 points, which is a 30 percent increase.
Why does this differ slightly from my calculator?
The output is rounded to four decimals and shown with thousands separators. The difference is that rounding, not the formula.
What happens if the base is zero?
Division by zero is undefined, so a dash appears instead of a number. Percentage change from zero is equally meaningless and stays blank.