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Percentage Calculator

Quickly work out percentages, percentage increases, decreases, and reverse percentages.

Enter percentage details

Use this calculator to find what percentage one number is of another, or to work out percentage changes.

Result
40.00
20% of 200 is 40.
Calculated amount
40.00
Percentage result
20.00%
Input one
20.00
Input two
200.00

Calculation breakdown

Mode What is X% of Y?
First value 20.00
Second value 200.00
Result 40.00

How This Percentage Calculator Works

This percentage calculator helps you solve several common percentage problems in one place, including finding a percentage of a number, working out percentage increases and decreases, reversing a percentage increase, and comparing two values.

Depending on the mode you choose, the calculator uses the two input boxes in slightly different ways. For example, in percentage of mode, the first box is the percentage and the second is the number you want to apply it to.

For increase and decrease calculations, the tool compares an original value with a new value to show the percentage change. For reverse percentage mode, it works backwards from a final figure to estimate the original number before a percentage increase was applied.

It is useful for everyday maths, discounts, markups, growth rates, and quick percentage comparisons.

Calculation mode Select the type of percentage calculation you want to perform, such as percentage of a number or percentage increase.
First value This is usually the percentage, original value, final value, or first comparison figure depending on the mode selected.
Second value This is usually the base number, new value, percentage rate, or second comparison figure depending on the type of calculation.
Result The calculator shows the main answer along with a quick summary and supporting breakdown for clarity.
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Example Percentage Calculations

20% of 200
Percentage20%
Base number200
Calculation0.20 × 200
Result = 40
Percentage increase
Original value80
New value100
Difference20
Increase = 25%
Percentage decrease
Original value150
New value120
Difference30
Decrease = 20%
Reverse percentage
Final value120
Increase applied20%
Original value100
Start amount = 100

Percentage Calculator FAQs

This calculator helps you solve common percentage questions, including finding a percentage of a number, percentage increases, decreases, reverse percentages, and percentage differences.
To find a percentage of a number, divide the percentage by 100 and multiply it by the base number. For example, 20% of 200 is 40.
Subtract the original number from the new number, divide the difference by the original number, and then multiply by 100 to get the percentage increase.
Reverse percentage means working backwards from a final number to find the original value before a percentage increase was added.
It is accurate for standard percentage calculations and quick estimates, although it does not replace professional financial or mathematical advice for more advanced use cases.
Percentage difference compares two numbers and shows how far apart they are as a percentage, usually relative to the first value in this calculator.

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Discount Calculator Apply percentages to shopping and sale prices. VAT Calculator Add or remove tax percentages from prices. Profit Margin Calculator Use percentages in pricing and markup calculations.