Percentage of a number, without guesswork.

Multiply the reference value by the percentage expressed as a decimal.

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 percentage increase or decrease from an original value to a new value.

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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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Result = percentage ÷ 100 × total. A percentage may be above 100 or below zero when the real problem permits it.

PercentDock

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

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