# How to Calculate Percentage – Change and Difference

Knowing how to compute the level of a number is a major activity for some parts of life. For instance, you might have to know how to compute rate to gauge vehicle installments or decide the initial investment for a home.

Rate estimations are additionally significant in business and different expert settings, for example, while computing assessments or worker raises. In this article, we investigate what a rate is, the way to compute various parts of a rate and the kinds of rates.

Also you read How to Calculate Percentage – Change and Difference

## What is percentage?

Rate, which may likewise be alluded to as percent, is a negligible part of a number out of 100 percent. Rate signifies “per 100” and indicates a piece of an aggregate sum. For instance, 45% addresses 45 out of 100, or 45% of the aggregate sum.

Rate may likewise be alluded to as “out of 100” or “for each 100.” For instance, you could say possibly “it snowed 20 days out of at regular intervals” or “it snowed 20% of the time.”

A rate might be written in more than one way. One way is to depict it as a decimal. For instance, 24% could likewise be composed as .24. You can track down the decimal rendition of a percent by isolating the rate by 100.

## How to calculate a percentage

The following formula is a common strategy to calculate a percentage:

### 1. Determine the total amount of what you want to find a percentage

For example, if you want to calculate the percentage of days it rained in a month, you would use the number of days in that month as the total amount. So, let’s say we are evaluating the amount of rain during the month of April’s 30 days.

### 2. Divide the number to determine the percentage

Using the example above, let’s say that it rained 15 of the 30 days in April. You would divide 15 by 30, which equals 0.5.

### 3. Multiply the value by 100

Continuing with the above example, you would multiply 0.5 by 100. This equals 50, which would give you the answer of 50%. So, in April, it rained 50% of the time.

Related: What is Aptitude?

## Types of percentage problems

There are three main types of percentage problems you might encounter in both personal and professional settings. These include:

### 1. Finding the ending number

Coming up next is an illustration of an inquiry that would expect you to utilize a rate estimation to find the completion number in an issue: “What is half of 25?” For this issue, you as of now have both the rate and the entire sum that you need to track down a level of.

Since you as of now have the rate, you will duplicate the rate by the entire number. For this situation, you would duplicate half, or 0.5, by 25. This offers you a response of 12.5. Hence, the solution to this rate issue would be “12.5 is half of 25.”

### 2. Finding the percentage

If you need to find the percentage, a question may be posed as “What percent of 5 is 2?” In this example, you will need to determine in a percentage how much of 2 is part of the whole of 5. For this type of problem, you can simply divide the number that you want to turn into a percentage by the whole. So, using this example, you would divide 2 by 5. This equation would give you 0.4. You would then multiply 0.4 by 100 to get 40, or 40%. Thus, 2 is equal to 40% of 5.

### 3. Finding the starting number

A percentage problem that asks you to find the starting number may look like “45% of what is 2?” This is typically a more difficult equation but can easily be solved using the previously mentioned formula. For this type of percentage problem, divide the whole by the percentage given. Using the example, you divide 2 by 45% or .45. This would give you 4.4, which means that 2 is 45% of 4.4.

## How to calculate percentage change

A rate change is a numerical worth that means the level of progress over the long run. It is most often utilized in money to decide the adjustment of the cost of a security over the long run. This equation can be applied to any number that is being estimated over the long run.

A rate change is equivalent to the adjustment of a given worth. You can settle a rate change by isolating the entire worth by the first worth and afterward increasing it by 100. The recipe for settling a rate change is the accompanying:

1. At a cost or rate increment:
2. [(New Price – Old Price)/Old Price] x 100
3. At a cost or rate decline:
4. [(Old Price – New Price)/Old Price] x 100
5. Here is an illustration of a cost/rate increment:

A TV cost \$100 last year however presently costs \$125. To decide the cost increment, you would take away the old cost from the new cost: 125 – 100 = 25. You would then isolate this by the old cost: 25 separated by 100 equivalents 0.25. You will then duplicate this number by 100: 0.25 x 100 = 25, or 25%. In this way, the TV cost has expanded by 25% over the course of the last year.

An illustration of a cost/rate decline:

A TV cost \$100 last year however presently costs just \$75. To decide the cost decline, you would take away the new cost from the old cost: 100 – 75 = 25. You will then isolate this number by the old cost: 25 separated by 100 equivalents 0.25. You would then duplicate this by 100: 0.25 x 100 = 25. or then again 25%. This implies the TV costs 25% short of what it did in the earlier year.

## How to calculate percentage difference

You can utilize rates to look at two changed things that are connected with one another. For instance, you might need to decide how much an item cost last year versus how much a comparable item costs this year. This estimation would give you the percent contrast between the two item costs.

Coming up next is the equation used to compute a rate contrast:
|V1 – V2|/[(V1 + V2)/2] × 100

In this equation, V1 is equivalent to the expense of one item, and V2 is equivalent to the expense of the other item.

An instance of utilizing this equation to decide the distinction between item expenses would include:

An item cost \$25 last year and a comparable item costs \$30 this year. To decide the rate contrast, you would initially deduct the expenses from one another: 30 – 25 = 5. You would then decide the normal of these two expenses (25 + 30/2 = 27.5). You will then isolate 5 by 27.5 = 0.18. You will then duplicate 0.18 by 100 = 18. This implies that the expense of the item this year is 18% more than the expense of the item from the year before.