How to use Percentage Calculator
Calculate percentages, percentage change, and portions.
- Choose the operation and enter every labeled input, keeping units and the time period consistent.
- Calculate, compare the worked example below and inspect any warnings.
- Change one assumption to compare another scenario; keep the model’s limits in view.
Formula & calculation method
Percentage of a number = X ÷ 100 × Y. Percentage change = (Y − X) ÷ |X| × 100. X as a percentage of Y = X ÷ Y × 100.
Input reference · 3 fields
These labels describe the calculation’s base units. Supported measurements can switch through the header’s region settings; follow the current workspace labels. Prefilled values are examples.
- Calculation
- Choose: Percentage of a number, Percentage change, X as a percentage of Y.
- X
- Enter a plain number with a decimal point if needed. The workspace shows an illustrative value, not a recommendation.
- Y
- Enter a plain number with a decimal point if needed. The workspace shows an illustrative value, not a recommendation.
A quick example
20% of 250 is 50. A rise from 100 to 120 is a 20% increase.
Assumptions, edge cases & limits
- Percentage change from zero is undefined.
- A percentage-point difference is not the same operation as relative percentage change.
Questions about Percentage Calculator
What is the difference between percent change and percentage points?
A move from 20% to 25% is a rise of 5 percentage points, but a relative increase of 25%. Choose Percentage change with 20 as the starting value and 25 as the new value for the latter.
Why can I not calculate percentage change from zero?
The change formula divides by the magnitude of the starting value. Division by zero is undefined, so an absolute change may be more useful for that comparison.
Are my files or inputs uploaded?
Calculation and file processing run in your browser without a processing upload. Downloads go to your device. Choosing a next-step transfer creates a temporary local copy for that workflow. Region preferences are stored separately from tool inputs. See our privacy details.
Can I use this tool for free?
Yes. No signup, subscription or payment is required to use the tool or download its output. File tools have device and size limits; a smaller batch may work better on a phone.
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