What this Percentage Calculator does

This percentage calculator helps you solve common percent problems without manual math. You can find what percent one number is of another, calculate a percentage of a value, or measure percentage increase and decrease.

Percentages are used everywhere: in shopping discounts, finance, school work, sports stats, business reports, and simple everyday decisions. A good percentage tool makes these calculations quick and easy.

Why it matters

Many people search for percentage answers when they want to compare values, check sales, or understand change over time. This page gives a simple, easy-to-read explanation along with a calculator section you can later connect to your code.

How to calculate percentages

Percent means “per hundred.” To find a percentage of a number, convert the percent into a decimal and multiply it by the number. For comparison and change, use the starting value and ending value to find the difference.

Step 1: Choose the type of calculation

Decide whether you want percent of a number, percentage increase, percentage decrease, or percent change.

Step 2: Enter the values

Type in the numbers required for your chosen calculation. For discount and change problems, make sure you know which number is the original value.

Step 3: Read the result

The calculator shows the answer instantly so you can use it for shopping, work, or study.

Formula

Percent of a number: (percent ÷ 100) × number

Percentage change: ((new – old) ÷ old) × 100

Percentage increase: ((new – old) ÷ old) × 100

Percentage decrease: ((old – new) ÷ old) × 100

Example calculation

Example: What is 20% of 150?

0.20 × 150 = 30.

So, 20% of 150 is 30.

Example: A price increases from 80 to 100.

Percentage increase = ((100 – 80) ÷ 80) × 100 = 25%.

Common uses of Percentage Calculator

Sale and discount calculations.
Grade and score percentage checks.
Price increase and decrease tracking.
Finance, tax, and budget comparisons.

Frequently asked questions

How do I find a percentage of a number?

Multiply the number by the percent written as a decimal. For example, 25% of 80 is 0.25 × 80.

How do I calculate percentage increase?

Subtract the original value from the new value, divide by the original value, then multiply by 100.

How do I calculate percentage decrease?

Subtract the new value from the original value, divide by the original value, then multiply by 100.

Percentage Calculator