Percentage calculator

Find a percentage of a number and add or subtract it.

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Percentage calculator processes your input in this browser. Inputs and results are excluded from analytics. Recent tools save tool names, visit counts and last-visit times. Saved tools store only their names. Draft saving is optional and stays on this device; delete saved text with the draft controls. Loading text from a URL is optional and contacts that server; its URL and your IP address are visible to the server. An optional “Use in” action keeps a handoff in this tab. The next tool removes it on arrival and ignores it if more than a minute has passed.

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Percentage (%)

Base amount

Answer

…

Percentage amount = base × percentage ÷ 100. Add or subtract that amount to adjust the base.

More results

Precision and calculation record

Decimal places in numeric results and text downloads

Rounding changes displayed numbers, not the calculation. Text, fractions, matrices and CSV schedules keep their own formatting. Automatic keeps up to 12 significant digits, with money shown to cents where applicable.

Step-by-step calculation

Inputs are substituted below. Each line evaluates the next operation; intermediate values are displayed to 12 significant digits while the calculation uses full precision.

Saved scenario

Save the current answer, then change an input to compare. This clears when you leave.

Formula and assumptions

A negative percentage reverses the direction. This is not percentage difference between two values.

Automatic precision shows numbers to 12 significant digits. Thousands separators such as 1,000 are accepted; use a dot for decimals.

Ask a percentage question in another way

Your question

Scratch calculator

Check another calculation

Use +, −, ×, ÷, parentheses and %. A percentage is divided by 100. This does not change the main tool.

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Keyboard shortcuts

Updated 2026-09-26

Using Percentage calculator

Percentage amount = base × percentage ÷ 100. Add or subtract that amount to adjust the base.

A negative percentage reverses the direction. This is not percentage difference between two values.

Next: Discount calculator

A worked example

With percentage (%) = 15, base amount = 200, the percentage amount is 30.

Next: Percentage change calculator

Before you use the result

A negative percentage reverses the direction. This is not percentage difference between two values.

Example results for percentage (%)

These examples use Base amount: 200. They are reference calculations, not recommended settings.

Percentage (%)	Percentage amount
7.5	15
15	30
30	60

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ToolOctopus. “Percentage calculator.” Updated 2026-09-26. https://tooloctopus.com/percentage-calculator.

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