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/100) × y

Example:

Find 40% of 200.

40% × 200 = (40 / 100) × 200 = 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 (increase).

100% × (80 - 60) / 60 = 33.33%

When the result is negative, we have percentage decrease.

Example:

Percentage change from 80 to 60 (decrease).

100% × (60 - 80) / 80 = -25%

Discount Calculator

When do we use percentages the most? They are great for expressing sales, because they tell us how much money do we get off the original price. More specifically – percentages show a share of the price, that we won't have to pay. So we know, how convenient or inconvenient the offer is and how much money it will save us. That's why it's so important to understand sale price calculations.