How do I find what percent one number is of another?

Divide the first number by the second number and multiply by 100. The second number cannot be zero.

How is percentage increase calculated?

Subtract the old value from the new value, divide by the old value, and multiply by 100.

The calculator returns an undefined readout because percentage division by zero is mathematically invalid.

ম্যাথ

Use a 3-in-1 percentage calculator for X percent of Y, X as a percent of Y, and percentage increase or decrease between two values.

Key terms

Calculation mode

X value

Y value

X% of Y = X/100 x Y; X as % of Y = X/Y x 100; Change % = (Y - X)/X x 100

The calculator switches formulas based on the selected percentage mode and guards against division by zero by returning an undefined result readout.

1Choose the percentage mode that matches the question.
2Enter X and Y values as the two quantities in the selected formula.
3For division-based modes, the denominator must be non-zero.
4Read the instant result as either a raw value or percentage depending on the selected mode.

Reference

Compare common scenarios quickly. Scroll horizontally on smaller screens.

Reference 1

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Reference 3

Question	Inputs	Formula	Result
What is 20% of 500?	X=20, Y=500	20/100 x 500	100
45 is what % of 180?	X=45, Y=180	45/180 x 100	25%
Change from 800 to 1,000	X=800, Y=1,000	(1000-800)/800 x 100	25% increase

Divide X by 100 and multiply by Y. For example, 20% of 500 is 20/100 x 500 = 100.

20% of 500

100