# %Percentage Calculator

## FAQ

Percentage calculator is a free online tool for calculating percentages.

#### What is a percentage?

A percentage is a way to express a number as a fraction of 100. It is often represented by the symbol "%".

#### How is a percentage calculated?

A percentage is calculated by multiplying a number by a certain percentage in decimal form. For example, to find 20% of 50, you would multiply 50 by 0.20.

#### What is the relationship between a percentage and a decimal?

A percentage is related to a decimal by the equation: percentage = (decimal) x 100. For example, 50% is equivalent to 0.50 as a decimal.

#### How do you convert a percentage to a decimal?

To convert a percentage to a decimal, divide the percentage by 100. For example, to convert 50% to a decimal, you would divide 50 by 100, which equals 0.50.

#### How do you convert a decimal to a percentage?

To convert a decimal to a percentage, multiply the decimal by 100. For example, to convert 0.50 to a percentage, you would multiply 0.50 by 100, which equals 50%.

#### What is a percentage increase or decrease?

A percentage increase or decrease refers to the change in a quantity as a percentage of the original quantity.

#### How do you calculate a percentage increase?

To calculate a percentage increase, you need to find the difference between the original value and the new value, divide it by the original value, and then multiply the result by 100.

#### How do you calculate a percentage decrease?

To calculate a percentage decrease, you need to find the difference between the original value and the new value, divide it by the original value, and then multiply the result by 100. The result will be a negative percentage.

#### Where did the concept of percentages originate?

The concept of percentages originated in ancient Mesopotamia and Egypt, where it was used to express quantities of goods in terms of fractions of 100.

#### When did the use of percentages become widespread?

The use of percentages became widespread during the Middle Ages, when merchants and traders used them to express proportions of goods for trade and taxation.

#### Who is credited with popularizing the use of percentages in mathematics?

The Italian mathematician Fibonacci is credited with popularizing the use of percentages in mathematics in his book "Liber Abaci" written in 1202.

#### How are percentages typically represented?

Percentages are typically represented by the symbol "%" and are often used in financial and economic contexts, such as in interest rates, tax rates, and investment returns.

#### How are percentages used in everyday life?

Percentages are used in everyday life in a variety of ways. For example, in cooking, recipes often use percentages to indicate the proportion of ingredients. In personal finance, percentages are used to express interest rates and other financial ratios. In sports, percentages are used to measure performance statistics.

#### How are percentages used in the field of statistics?

Percentages are used in statistics to express proportions of a whole. For example, in a survey, the percentage of respondents who answered a certain way can be calculated. Additionally, percentages are used to calculate confidence intervals and margin of error in sample surveys.

#### How can percentages be used to compare two or more quantities?

Percentages can be used to compare two or more quantities by expressing them as a fraction of 100. For example, if a company's sales increased by 20% from the previous year, this can be compared to the sales of a competitor that only increased by 10%.

#### How can percentages be used to calculate growth or decline?

Percentages can be used to calculate growth or decline by comparing a current value to a previous value. For example, if a company's sales were $100,000 last year and $120,000 this year, the growth rate can be calculated as (120,000 - 100,000) / 100,000 * 100 = 20%

#### How are percentages used in finance and economics?

Percentages are widely used in finance and economics. For example, interest rates on loans and investments are often expressed as a percentage. Inflation is often measured as the percentage change in the Consumer Price Index (CPI) over a given period of time. Stock prices are often reported as the percentage change from the previous closing price.

#### Are there any disadvantages or limitations to using percentages?

Yes, there are some disadvantages and limitations to using percentages. For example, percentages can be misleading when used to compare quantities with very different units or magnitudes. Additionally, percentages don't always provide a clear picture of the underlying values, leading to misinterpretation or overgeneralization.

#### What is the history of percentages?

Long before the existence of the decimal system, in Ancient Rome, calculations were often made in fractions in multiple of 1 over 100. For example, a tax of 1 / 100th on goods sold at auction was known as *centesima rerum venalium*. Calculations using these fractions was the equivalent of calculating percentages.

During the Middle Ages, as denominations of monies grew, calculations with a denominator of 100 became increasingly commonplace, and from the late 15th to the early 16th century, it was becoming common for arithmetic writings to include these calculations. These writings applied these methods to interest rates, profit and loss, and the Rule of Three. By as early as the 17th century, it was standard to quote interest rates in hundredths.

#### Where does the term *percent* come from?

The term “percent” is taken from the Latin *per centum*, meaning “by the hundred” or simply “hundred”.

#### Where did the percentage sign evolve?

The percent sign (%) developed by gradual contraction of the Italian term *per cento* (which meant “for a hundred”). The *per* was often contracted to a simple *p.* - eventually disappearing entirely. The *cento* was contracted into two circles, separated by a horizontal line, forming the modern % symbol we use today.

#### What’s the difference between the term’s percentage and percent?

The Cambridge English Dictionary define “percentage” as *an amount of something, often expressed as a number out of 100*, and “percent” as *for or out of every 100, shown by the symbol %*. The two words are used interchangeably.

#### How to calculate percentages?

A percent value is calculated by first multiplying a numeric value of the ratio of two widgets by 100. For example, to find how many 60 oranges are of a percentage of a shipment of 300 oranges, we divide 60 by 300, which is 0.2. Then we multiply this value by 100, with the result being that 60 oranges are 20% of the 300-orange shipment.

Another, although less common, method of calculating a percentage is to first multiply the 60 oranges by 100, then dividing by the total number in the shipment, which gives the same result. That is to say (60 * 100) / 300 = 20%.

#### How to calculate a percentage of a percentage?

When calculating a percentage of percentage, first convert both of your percentages to fractions of 100 (or to decimals), the multiply them. For example, 80% of 50% is calculated by:

80/100 = 0.8 multiplied by 50/100 = 0.5, and 0.8 multiplied by 0.5 is 0.4, or 40%.