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Percentage Calculator

Percentages show up in tips, discounts, tax, grades and interest. This solves the three questions people ask most: what is a percentage of a number, what percent one number is of another, and what whole a part came from.

Your numbers

In most modes, A is the percentage.

The reference value.

Result

Result
20
In words
10% of 200 = 20
Step by step
StepDetail
OperationWhat is A% of B
Formula10% × 200 ÷ 100
Result10% of 200 = 20
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What is A% of B

Multiply the number by the percentage and divide by 100: B × A ÷ 100. So 10% of 200 is 200 × 10 ÷ 100 = 20. A quick shortcut for 10% is to move the decimal one place; for 1%, move it two.

A is what percent of B

Divide the part by the whole and multiply by 100: A ÷ B × 100. If 20 out of 200 questions were correct, that is 20 ÷ 200 × 100 = 10%. This is the mode for test scores, completion rates and "what share is this".

Finding the whole from a part

If A is B% of some number, recover the whole with A ÷ (B ÷ 100). When $30 is 15% of a total, the total is 30 ÷ 0.15 = $200. Useful for reversing a tip, tax or commission back to the base amount.

Frequently asked questions

Sources

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