Percentages Calculator

How do you calculate Percentage manually?

You can calculate a percentage manually by dividing the part by the whole and multiplying the result by 100. This percentage formula expresses the part as a fraction of 100.

Formula:

Step by step guide

1. Identify the part and the whole value.
2. Divide the part by the whole.
3. Multiply the decimal result by 100.
4. Add the percent sign (%) to the result.

For example, if 30 students out of a total of 120 students pass an exam:

$\frac{30}{120} = 0.25$

Then multiply the decimal by 100:

$0.25 \times 100 = 25$

Practical Example

Suppose a store sells 45 products from a total stock of 60 products. Divide the items sold by the total stock and multiply by 100:

$\frac{45}{60} \times 100 = 75$

The store sold 75% of its total stock. The same method works for exam scores, discounts, tips, taxes, sales, and other percentage calculations.

How to calculate percentages in Excel?

In Excel, divide the part by the total using cell references. For example, enter =B2/C2 if B2 contains the part and C2 contains the whole, then apply Percent Style. You can also use:

Use this version when you want a numeric percentage value rather than Excel's percentage formatting. Copy or Autofill the spreadsheet formula to calculate percentages across multiple rows.

How To Convert Percentage to Decimal?

Convert a percentage to a decimal by removing the percent sign and dividing the percentage value by 100:

For example:

$35$

This process moves the decimal point two places to the left. To reverse the conversion, multiply the decimal by 100 and add the percent sign.

Common Percentage Calculations

Common percentage calculations help you find a percentage of a number, measure increases or decreases, compare values, and recover an original value.

Percentage of a Number

To find a percentage of a number, convert the percent to a decimal and multiply it by the number. For example:

$25$

This formula works for discounts, taxes, tips, exam scores, interest, and other percentage amounts.

Percentage Increase

Percentage increase measures how much a new value rises relative to the original value. Use:

If a value rises from 80 to 100, the percentage increase is 25%.

Percentage Decrease

Percentage decrease measures how much a value falls relative to its original value. Use:

A decrease from 100 to 80 equals a 20% decrease from the initial value.

Percentage Difference

Percentage difference compares two values without treating either value as the original baseline. Use their absolute difference and average:

This calculation shows the relative magnitude of the difference between two numbers.

Reverse Percentage

Reverse percentage finds the original value when you know the final value after a percentage increase or decrease. For a percentage increase:

For a decrease, replace the plus sign with a minus sign.