Percentage means out of 100, which means divide by 100. Percentage calculator is an online tool to calculate the percentage of value from an amount of total. You can also use the tool to determine what is the % of increase or decrease in a value.

The term "percent" is derived from the Latin per centum, meaning hundred or by the hundred. The percent value is computed by multiplying the numeric value of the ratio by 100.

The concept of percentage is an extension of the material we have covered about fractions and ratio. To allow easy comparisons of fractions we need to use the same denominator. As such, percentages use 100 as the denominator. In other words, the ‘whole’ is divided into 100 equal parts. The word “per cent” means per 100. Therefore 27% is 27 / 100 .

To use percentage in a calculation, the simple mathematical procedure is modelled below where we write the percentage as a fraction with a denominator of 100. For example: 25% is 25 / 100, thus to calculate 25%of 40, we could approach it as (25 / 100) × (40 / 1)=10

Percentages are most commonly used to compare parts of an original. For instance, the phrase 30% off sale! indicates that whatever the original price, the new price will be 30% less.

However, percentages are rarely as simple as 23% of 60. Percentages are more commonly used as part of a more complex question. Often the question is, “How much is left?” or “How much was the original?”