Use this **percentage calculator** to determine how much a percent represents from a given value or what % is a value compared to another absolute value; or you can use it to estimate a percentage increase or decrease based on the given data. More details on this topic you can find below the tool.

## What is a percentage?

It was first defined in mathematics and nowadays is one of the most used calculations across the world because it can easily help in defining or describing any quantitative problem in a quick, concise and easy to remember way. The percentage denoted as %, abbreviated as pct. and known as percent represents a number or a ratio expressed as a fraction of 100.

For instance, 25% (read as "twenty-five percent") equals 25/100, or in decimal format equals 0.25. As stated above the usability of percentage is very high since it helps in expressing how large or small one number, quantity or value is relative to another number, quantity or value.

Please note that in order to have relevancy a percentage should be obtained by comparing two values that must relate one to each other.

Its high usability can be easily proved as today there are many percentage calculations made on a daily basis such as:

■ In special or seasonal promotions, how much does it represent this percentage discount from a certain sale price? It quickly shows how much you can save from original price and can help you decide whether you should take advantage of it or not.

■ Is 3.5% annual interest rate on fixed deposits a satisfying return rate for my savings? It quickly shows how much interest you can earn within a year from your investments account.

■ Why so many people, 67% voted for this candidate? It quickly shows that a majority voted for a certain candidate.

Three things to avoid when using percentages:

■ Please note that is incorrect to divide by 100 and use the percent sign at the same time. For instance 10% equals 10/100 or 0.10 but not 10%/100.

■ Please remember that when using percentage it is mandatory to mention what it is relative to the relative value you speak about.

■ Please note there is a huge difference between „percent” and „percentage point”**. **While the first concept is what we defined above, the percentage point represents the arithmetic difference between the numbers in percentage sizes.

## How to calculate percentage?

■ The percent value is calculated by multiplying the given value of the ratio by 100, for instance in order to find how much does 2,000 people represents as a percentage out of 25,000 people, first you need to make the ratio 2,000/25,000 = 0.08, and then multiply by 100 to obtain the final value of 8%. Another method that can be used in this situation assumes that you first should multiply the given value in this case 2000 by 100 which results in 20,000 then this value would be divided by 25,000 to obtain the same 8%.

■ A common calculation is a percentage of a percentage that requires you to convert both % to number expressed either as fractions of 100 or as decimals numbers and then multiply them. For instance 75% of 35% is computed this way: (75/100) * (35/100) = 0.75 * 0.35 = 0.2625 = 26.25/100 = 26.25%.

■ Another common calculation is when trying to define how much a certain % represent in absolute value from a certain number. For instance, how much does 50% represent in case of a population of 1 million? The answer is a half of a million which is obtained as (50/100) * 1,000,000 = 500,000.

When trying to perform these calculations you either have the option to make them on a paper basis as explained above or by using our percentage calculator.

## How to calculate percentage increase/decrease?

This concept should be explained separately since in many cases the usage of percentage is not consistent as it should be, mainly because of the fact that it is not always clear what a percentage is relative to.

For instance when referring to a "5% rise" or a "5% fall" in a given number or quantity, it usually means that this change is relative to the initial value.

Another example, if a product is initially on market at $100 and then the price rises 10% (which means an absolute increase of $10), then the price will change to $110, and so please note that the new price is 110% of the initial price.

The formula used to determine relative changes is applied by our *percentage calculator* and is explained in the next lines:

Percentage increase/decrease formula = [(Reference number – Initial Number)/Reference Number]*100.

If the result is positive then we call it decrease while in case it is positive then we call it increase.

23 Feb, 2015