Percentage Calculator
Calculate percentages, percentage increase/decrease, and find what percent one number is of another instantly.
Why Use Our Percentage Calculator?
Instant & Accurate
Get precise percentage calculations instantly. Whether it's simple percentages, increases, or decreases, our tool handles it all with 100% accuracy.
Versatile Modes
Switch easily between finding a percentage of a number, determining what percentage one number is of another, or calculating percentage change.
Learn the Math
We don't just give you the answer; we show you the formula and calculation steps so you can understand the math behind percentages.
What is a Percentage?
A percentage is a number or ratio expressed as a fraction of 100. It is denoted using the percent sign (%).
The word "percent" comes from the Latin per centum, meaning "by the hundred". For example, 50% means 50 per 100, or 50/100, or 0.50.
- 100% represents the whole.
- 50% represents half.
- 25% represents a quarter.
- 0% represents nothing.
Percentage Formulas
1. Percentage of a Number
Value = (Percentage ÷ 100) × Number
2. What Percentage is X of Y?
Percentage = (X ÷ Y) × 100
3. Percentage Change
Change % = ((New - Old) ÷ Old) × 100
Real-World Examples
🛍️ Discounts & Sales
Calculate how much you save during a sale. If a $50 shirt is 20% off, you save $10 and pay $40.
💰 Tips & Gratuity
Determine how much to tip at a restaurant. A 15% tip on a $100 bill is $15.
📈 Taxes
Calculate sales tax or income tax. If sales tax is 8%, a $100 item costs $108 total.
📊 Statistics
Analyze data changes, such as population growth, stock market fluctuations, or grade improvements.
Frequently Asked Questions
How do I calculate a percentage of a number?
To calculate a percentage of a number, convert the percentage to a decimal (divide by 100) and multiply it by the number. For example, to find 20% of 50: 0.20 × 50 = 10.
How do I calculate percentage increase?
Subtract the original number from the new number, divide the result by the original number, and multiply by 100. Example: increasing from 40 to 50 is a ((50-40)/40)×100 = 25% increase.
How do I calculate percentage decrease?
Subtract the new number from the original number, divide by the original number, and multiply by 100. Example: decreasing from 50 to 40 is a ((50-40)/50)×100 = 20% decrease.
What is the reverse percentage formula?
To find the original number before a percentage increase, divide the final number by (1 + percentage/100). For a decrease, divide by (1 - percentage/100).