Percentage Calculator
Easily calculate percentages using the three most common methods.
Other Calculators in This Category
Free Online Percentage Calculator – All Percentage Formulas Covered
Our online percentage calculator helps you solve all common percentage problems instantly and accurately. Whether you want to calculate what percentage one number is of another, figure out a percent increase or decrease, or reverse-calculate the total from a known percentage, this tool does it all. You can use this calculator on any device – no app or login required.
Available Percentage Calculations
This calculator supports the following use-cases:
- What is X% of Y? – Quickly find the portion of a number based on a given percentage.
- X is what % of Y? – Determine the percentage that one number represents of another.
- Percentage Increase/Decrease – Calculate the percent difference between two numbers.
- X is Y% of what? – Find the original total when you know the percentage and part.
1. What is X% of Y?
This is the most basic percentage calculation. It's useful in discounts, interest rates, grades, taxes, and more.
Formula: (X / 100) × Y
Example: What is 20% of 150? → (20 ÷ 100) × 150 = 30
2. X is What Percent of Y?
Use this to find the percentage that one number represents of another.
Formula: (X / Y) × 100
Example: 30 is what percent of 150? → (30 ÷ 150) × 100 = 20%
3. Percentage Increase/Decrease
This is commonly used in finance, statistics, e-commerce, or whenever values change over time.
Formula: ((New - Old) / Old) × 100
Example: From 120 to 150 → ((150 - 120) ÷ 120) × 100 = 25% increase
4. X is Y% of What?
This reverse percentage calculation helps find the original number when you know the percentage and result.
Formula: X ÷ (Y / 100)
Example: 30 is 20% of what? → 30 ÷ (20 ÷ 100) = 150
Common Uses of Percentage Calculators
- ✅ Shopping: Calculate sale discounts or price markups.
- ✅ Business: Determine profit margins, commission, or growth rates.
- ✅ Academics: Convert test scores to percentages.
- ✅ Finance: Calculate tax, interest, loan repayments, or salary raises.
- ✅ Statistics: Analyze data percentages and comparisons.
Why Use This Percentage Calculator?
This percentage calculator is fast, flexible, and covers all common formulas in one place. Unlike many basic tools, it lets you switch between multiple types of percentage problems using an easy tab-based interface.
- 🧮 All 4 essential formulas supported
- ⚡ Instant calculations without page reloads
- 📱 Mobile & desktop friendly
- 🆓 100% free, no sign-up required
FAQs – Percentage Calculator
Q: How do I calculate percentage manually?
You can divide the part by the whole, then multiply by 100: (part ÷ whole) × 100.
Q: Can I calculate percent increase and decrease with this tool?
Yes! Just use the third tab. Enter the old and new value and it will tell you the exact percentage change.
Q: Is this calculator free to use?
Absolutely. You can use it online without any charges or registration.
Q: Does it work on mobile?
Yes, it’s fully responsive and works on all screen sizes – desktop, tablet, and smartphone.
Try It Now
Use the percentage calculator above to quickly find the answers to your everyday percentage problems. Bookmark this tool for future use or share it with colleagues and friends.