## Calculate percentages in a few clicks

The percentage calculator will help you calculate any percent online. However, before we start, let's discuss the topic area.

Percentage is a common and useful mathematical concept used in everyday life to solve problems related to finance, business, science, and education. For example, it is used to calculate interest on a loan, discounts, taxes, profits, and more.

But it is not always possible to perform calculations quickly and accurately in your head or on a calculator. Additionally, sometimes difficult problems arise that require knowledge of specific formulas and rules. To solve this issue, an online percentage calculator has been developed, which solves the main issues with percentages in just a few clicks.

### How to Calculate Percentage of a Number

The term "percent" was borrowed from Latin, where "percentum" means "per hundred." A percentage is a fraction with a denominator of 100, that is, a ratio between a part and a whole, where the whole is equal to 100.

In mathematics, there are two ways to calculate percentage:

- Bringing the denominator of a fraction to 100;
- Unitary method.

The first method requires finding an equivalent fraction whose denominator is 100. The numerator of the specified fraction and will be equal to the desired percentage.

Example:17 ÷ 20 = 17 ÷ 20 × 5 ÷ 5 = 85 ÷ 100 = 85%

The second method requires multiplying the fraction by 100 and dividing.

Example:17 ÷ 20 × 100 = 1700 ÷ 20 = 85%.

## Proportion Calculator

The proportion calculator can calculate percentages online using the mathematical proportion property.

Proportion is a mathematical expression that states the equality of two ratios. Proportion can be used to solve various problems such as finding an unknown value in a proportion, finding percentages, solving triangles, etc. The proportion can be written as a ÷ b = c ÷ d, where a, b, c and d are numbers. a and d are called extreme terms, b and c are called middle terms.

Proportion shows how quantities are related to each other and how they change when increased or decreased. The main property of proportion is that the product of the extreme terms is equal to the product of the middle terms. This property can be used to test or solve problems.

### Example

For example, if 2 pounds of apples cost $4, how much do 5 pounds of apples cost? To solve this problem, let's create a proportion: 2 ÷ 4 = 5 ÷ X, where X is the unknown price of 5 pounds of apples. We know that the product of the extreme terms is equal to the product of the middle terms, we write: 2X = 4 × 5. From here we can express: X = 4 × 5 ÷ 2 = 10.

Answer: 5 pounds of apples cost $10.

### How to find 100% of a number

To find 100% of a number using a proportion, you need to create an equality of two ratios, where one of the terms is equal to 100%.

Example: if 20% of a number is 40, then how to find 100% of this number? Let's make a proportion: X ÷ 100 = 40 ÷ 20, Let's express X = 100 × 40 ÷ 20 = 200.

Answer: 100% of this number is equal to 200.

## What percentage is one number of another number?

In everyday life, we often need to know what part of one number is another. It could be useful in calculating discounts, taxes, commissions, and in various other situations.

There are several ways to find out what percentage one number is of another:

### Using proportion:

- Step 1: Write down that the first number X = ?
- Step 2: Write down that the second number is Y = 100
- Step 3: Make up the proportion: X × 100 = Y × ?
- Step 4: Solve the proportion for ? = X × 100 ÷ Y

EXAMPLE:

What percentage is 20 of 50?

- Step 1: Write down that 20 = ?
- Step 2: Write down that 50 = 100
- Step 3: Let's make a proportion: 20 × 100 = 50 × ?
- Step 4: Solve the proportion: ? = 20 × 100 ÷ 50 = 40%

### Using the formula:

To calculate the percentage of one number from another, you can use the following formula:

Part ÷ Whole × 100

EXAMPLE:

What percentage is 20 of 50?

20 ÷ 50 × 100 = 0.4 × 100 = 40%

## How to increase a number by a percentage

- Determine the percentage increase. This will be the number you want increase the original number. For example, if you want to increase a number by 15%, your percentage increase will be equal to 15.
- Calculate the percentage increase. Divide the percentage increase by 100 to get convert it to decimal form. For example, 15% becomes 0.15.
- Multiply the original number by the percentage increase. This will give you the number on which needs to be increased from the original number. For example, if your original number is 200, multiply 200 by 0.15 to get 30.
- Add the increase to the original number. This will give you the final number. For example, add 30 to 200 to get 230.

## How to reduce a number by a percentage

- Determine the percentage reduction. This will be the number you want reduce the original number. For example, if you want to reduce a number by 15%, your percentage reduction will be equal to 15.
- Calculate the percentage reduction. Divide the percentage reduction by 100 to convert it to decimal form. For example, 15% becomes 0.15.
- Multiply the original number by the percentage reduction. This will give you the number on which needs to be reduced from the original number. For example, if your original number is 200, multiply 200 by 0.15 to get 30.
- Subtract the decrease from the original number. This will give you the final number. For example, subtract 30 from 200 to get 170.

## How much greater or less is a number than another number?

If you want to find out by what percentage one number is greater or less than another number, you must use the following formula:

- If the number A is greater than the number B, then by what percentage is A greater than B is calculated by the formula (A – B) ÷ B × 100%.

- If the number A is less than the number B, then by what percentage is A less than B is calculated by the formula (B – A) ÷ B × 100%.

For example, if there are two numbers 20 and 40, then 40 is greater than 20 by (40 – 20) ÷ 20 × 100% = 100%, and 20 is less than 40 by (40 – 20) ÷ 40 × 100% = 50%.