Percentage Calculator | Math Tools

Percentage Calculator

Calculate percentages, increases, decreases, and more

%

Calculation Results

Result

–
Calculated value

Calculation

–
Formula used

Common Percentage Examples

20% of 100
= 20
Basic percentage calculation
10% increase of 100
= 110
Percentage increase
15% discount on 200
= 170
Percentage decrease
From 50 to 75
= 50% increase
Percentage change

What are Percentages?

Percentages show a number as part of 100, and they make it easier to compare values. The word “percent” means “per hundred,” so 25% means 25 out of 100 or 0.25 as a decimal. Because of this, percentages are often used in shopping, taxes, interest rates, and statistics.

Why Use a Percentage Calculator?

A percentage calculator helps you save time and avoid mistakes. It can be used in many ways, and below are some common examples:

Shopping

When shopping, you can quickly find discounts and final prices.

Finance

You can also work out interest, loan payments, or investment growth.

Data

In addition, percentages help you read statistics, surveys, and reports.

Cooking

Finally, you can use them to adjust recipes and check nutrition values.

Percentage Calculator Formulas

Here are some common percentage formulas you will use:

Basic Percentage

(X ÷ 100) × Y — for example, 20% of 50 is (20 ÷ 100) × 50 = 10.

Percentage Increase

Y × (1 + (X ÷ 100)) — this is useful when adding tax or markup.

Percentage Decrease

Y × (1 – (X ÷ 100)) — for example, when applying a discount.

Percentage Change

((New – Old) ÷ Old) × 100% — this shows how much a value has changed.

How to Use Our Percentage Calculator

The steps below show how the percentage calculator works from start to finish:

1

Pick a Calculation

First, choose basic, increase, decrease, or change.

2

Enter Numbers

Next, type the values you want to calculate.

3

Click Calculate

Then, press the button to get the result.

4

View Result

Finally, see the answer and the formula used.

Where We Use Percentages

Percentages appear in many fields, and here are a few common examples:

  • Finance: loans, savings, and interest rates
  • Retail: discounts, sales, and taxes
  • Education: grades, test scores, and statistics
  • Health: body fat and nutrition labels
  • Sports: scores and performance rates

Frequently Asked Questions

How do I calculate a percentage?

You divide the part by the whole and multiply by 100. For example, (25 ÷ 100) × 100 = 25%.

How do I add a percentage?

You multiply the number by (1 + percentage ÷ 100). For example, 100 × 1.1 = 110.

How do I subtract a percentage?

You multiply the number by (1 – percentage ÷ 100). For example, 200 × 0.85 = 170.

What is percentage difference?

You take |New – Old| ÷ Old × 100%. For example, |100 – 80| ÷ 80 × 100 = 25%.

Where are percentages used?

They are used in shopping, finance, school, health, and sports because they make values easy to compare.