Percentage Calculator
Find a percentage of a value, percentage change, or the percentage represented by a part. See substituted numbers, steps and a number line.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
A percentage represents a value per hundred. Divide a rate by 100 before multiplying. For percentage change, divide the difference by the original value; for a part-to-whole percentage, divide the part by the whole and multiply by 100.
Part = A × B/100; change = (B − A)/A × 100%; ratio = A/B × 100%
Worked example
15% of 200 = 30. A change from 200 to 230 is (230 − 200)/200 × 100 = 15%. A part of 30 out of 200 is also 15%.
Assumptions and input details
Percentage change from zero is undefined. Negative starting values are allowed, but their signed-base percentage can be unintuitive; read the displayed formula. Percent change and percentage-point difference are distinct concepts.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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