Percentage Calculator
This free percentage calculator helps you instantly calculate percentages, percentage increase, percentage decrease, and percentage of a number. It is designed for students, professionals, shoppers, business owners, and anyone who works with percentages daily.
Percentages are used everywhere in real life — from discounts and taxes to statistics and finance. This calculator simplifies all common percentage calculations in one place.
What Is a Percentage?
A percentage represents a number as a fraction of 100. The word "percent" literally means "per hundred." Percentages make it easy to compare values relative to a whole.
For example:
25% means 25 out of 100
Percentages are written using the % symbol and are commonly used to express proportions, changes, and comparisons.
Basic Percentage Formula
The most common percentage formula is:
Percentage = (Part ÷ Whole) × 100
This formula tells you what percent one value represents of another.
Example:
If you scored 45 points out of 60:
(45 ÷ 60) × 100 = 75%
How This Percentage Calculator Works
This calculator uses the standard percentage formula. When you enter a value and a percentage, the calculator:
Step 1: Converts the percentage into decimal form
Step 2: Multiplies it by the value
Step 3: Displays the result instantly
This ensures fast and accurate results without manual calculations.
Calculating Percentage of a Number
To calculate a percentage of a number, use the formula:
Result = (Percentage ÷ 100) × Number
Example:
20% of 150:
(20 ÷ 100) × 150 = 30
This calculation is commonly used for discounts, tips, commissions, and taxes.
Percentage Increase Explained
Percentage increase shows how much a value has grown compared to its original amount.
Formula:
Percentage Increase = ((New − Original) ÷ Original) × 100
Example:
If a price increases from 80 to 100:
((100 − 80) ÷ 80) × 100 = 25% increase
Percentage Decrease Explained
Percentage decrease measures how much a value has reduced compared to its original amount.
Formula:
Percentage Decrease = ((Original − New) ÷ Original) × 100
Example:
If a product price drops from 200 to 150:
((200 − 150) ÷ 200) × 100 = 25% decrease
Percentages in Daily Life
Percentages are used in many everyday situations, such as:
• Shopping discounts and sales
• Bank interest rates
• Tax calculations
• Exam scores and grades
• Business growth and profit margins
• Tip calculations at restaurants
Understanding percentages helps you make better financial and analytical decisions.
Common Percentage Mistakes
A common mistake is confusing percentage points with percentages.
Another mistake is forgetting to divide by 100 when converting a percentage into a decimal.
Incorrect: 10% = 10 (forgetting to divide by 100)
Correct: 10% = 0.10 (dividing by 100 correctly)
Why Use an Online Percentage Calculator?
Manual percentage calculations can be time-consuming and error-prone.
An online percentage calculator provides instant, accurate results and works on all devices without installation.
Frequently Asked Questions
Can percentages be greater than 100?
Yes. Percentages can exceed 100 when a value is larger than the original reference.
Is zero allowed?
Yes. A value of zero always results in zero percent.
Are decimal percentages supported?
Yes. This calculator works with decimal percentage values as well.
Conclusion
Percentages are one of the most practical mathematical concepts in everyday life. This percentage calculator makes calculations fast, accurate, and easy to understand.
Whether you are shopping, studying, or managing finances, this tool helps you work with percentages confidently.