Percentage (%)

Percentage is per-cent which means parts per hundred.
One percent is equal to 1/100 fraction:

1% = 1/100 = 0.01

Ten percent is equal to 10/100 fraction:

10% = 10/100 = 0.1

Fifty percent is equal to 50/100 fraction:

50% = 50/100 = 0.5

One hundred percent is equal to 100/100 fraction:

100% = 100/100 = 1

One hundred and ten percent is equal to 110/100 fraction:

110% = 110/100 = 1.1

Percent sign

The percent sign is the symbol: %
It is written to the right side of the number: 50%

Percentage Definition

Percentage is a value that represents the proportion of one number to another number.
1 percent represents 1/100 fraction.
100 percent (100%) of a number is the same number:

100% × 80 = 100/100×80 = 80

50 percent (50%) of a number is half of the number:

50% × 80 = 50/100×80 = 40

So 40 is 50% of 80.

Percentage of a Value Calculation

x% of y is calculated by the formula:

percentage value = x% × y = x × y / 100

Example:

Find 40% of 200.

40% × 200 = 40 × 200 / 100 = 80

Percentage Calculation

The percentage of x from y, is calculated by the formula:

percentage% = (x / y) × 100

Example:

The percentage of 30 out of 60.

30 / 60 × 100 = 50%

Percentage Change (increase/decrease)

Percentage change from x1 to x2 is calculated by the formula:

percentage change = 100 × (x2 - x1) / x1

When the result is positive, we have percentage growth or increase.

Example:

Percentage change from 60 to 80.

100 × (80 - 60) / 60 = 33.33% increase

When the result is negative, we have percentage decrease.

Example:

Percentage change from 80 to 60.

100 × (60 - 80) / 80 = -25% decrease