Percentage change calculator with a clear direction.

Compare the difference with the absolute starting value and report increase or decrease.

Percentage questions

Percentage

Reference number

Part

Ratio reference

Starting value

New value

Result

20% of 80

16 as a % of 80

20%

80 → 100

25%

increase

Processed locally — inputs and results stay in this browser tab. Copy and download actions run only when you choose them.

Calculate percent of a number, ratios, and percentage change with visible formulas.

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Calculate any percentage of a number with a visible formula.

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Worked explanations for percent-of, ratio, percent change, reverse percentages, and percentage points.

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How PercentDock processes numeric inputs locally.

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Standard percentage change is undefined when the starting value is zero because the denominator would be zero. Report the absolute change instead.

PercentDock

Work out shares, changes, markups, and reverse percentages.

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