Percentage Calculator
Calculate percentages in three different modes — free and private
Quick examples
What is a Percentage Calculator?
A percentage calculator is a tool that helps you quickly calculate percentages in various scenarios. Whether you need to find a percentage of a number, calculate percentage change, or determine a ratio, this tool provides instant, accurate results.
Our free online percentage calculator works in three modes and all calculations happen locally in your browser — your numbers are never sent to any server, ensuring complete privacy.
💡 Why use a percentage calculator? Percentages are everywhere — in shopping discounts, tips, grades, financial reports, and data analysis. This tool helps you calculate them instantly, accurately, and without mental math errors.
Three Calculation Modes
1. Percentage of a Number
Find what percentage of a number is. For example: 25% of 200 = 50. This is useful for calculating discounts, tips, taxes, and commissions.
Formula: (Percentage × Number) ÷ 100 = Result
2. Change by Percentage
Increase or decrease a number by a percentage. For example: Increase 200 by 25% = 250. This is useful for calculating price changes, salary increases, and growth rates.
Formula: Number × (1 ± Percentage/100) = Result
3. Percentage Ratio
Calculate what percentage one number is of another. For example: 50 is 25% of 200. This is useful for comparing values, analyzing proportions, and understanding distributions.
Formula: (Number A ÷ Number B) × 100 = Percentage
Percentage Formulas Quick Reference
| Calculation Type | Formula | Example |
|---|---|---|
| Percentage of a number | (P × N) ÷ 100 |
25% of 200 = 50 |
| Percentage increase | N × (1 + P/100) |
200 + 25% = 250 |
| Percentage decrease | N × (1 - P/100) |
200 - 25% = 150 |
| Percentage ratio | (A ÷ B) × 100 |
50 is 25% of 200 |
| Percentage change | ((New - Old) ÷ Old) × 100 |
From 200 to 250 = +25% |
Common Use Cases
Who Uses a Percentage Calculator?
- Shoppers — Calculating discounts and sale prices
- Business owners — Computing profit margins, markups, and growth
- Students — Solving math problems and calculating grades
- Financial analysts — Analyzing data and trends
- Teachers — Creating tests and grading assignments
- Restaurant staff — Calculating tips and bill splits
- Real estate agents — Calculating commissions and price changes
- Anyone — Dealing with percentages daily
Why Use Our Percentage Calculator?
- 100% free and unlimited — No sign-up, no hidden fees, no limits
- Three modes in one tool — All common percentage calculations
- Instant results — See calculations as you type
- Visual bar chart — Visual representation of results
- Quick examples — Try common scenarios with one click
- Privacy-first — All calculations happen in your browser
- No ads — Clean, distraction-free experience
- Mobile friendly — Works on phones, tablets, and desktops
How to Calculate Percentages: Step-by-Step
- Choose your mode — Select from "Percentage of number", "Change by percent", or "Percentage ratio"
- Enter your numbers — Fill in the input fields with your values
- Get instant results — The result appears automatically as you type
- Review all metrics — See the main result, original number, final number, difference, and percent change
- Visualize the result — View the bar chart for a visual representation
Frequently Asked Questions
What is the formula for calculating a percentage of a number?
The formula is: (Percentage × Number) ÷ 100 = Result. For example, 25% of 200 = (25 × 200) ÷ 100 = 50.
What is the formula for percentage change?
The formula is: ((New Value - Original Value) ÷ Original Value) × 100 = Percentage Change. A positive result means an increase, and a negative result means a decrease.
How do I calculate a discount?
To calculate a discount, multiply the original price by the discount percentage and divide by 100. For example, 20% off $150 = (20 × 150) ÷ 100 = $30 discount, so the final price is $120.
How do I calculate a tip?
To calculate a tip, multiply the bill amount by the tip percentage and divide by 100. For example, 15% tip on $45 = (15 × 45) ÷ 100 = $6.75.
How do I calculate my grade percentage?
To calculate your grade percentage, divide your score by the total possible and multiply by 100. For example, 18 out of 20 = (18 ÷ 20) × 100 = 90%.
What is the difference between percentage increase and percentage decrease?
Percentage increase is when a value grows, calculated as ((New - Original) ÷ Original) × 100. Percentage decrease is when a value shrinks, calculated as ((Original - New) ÷ Original) × 100.
Is this percentage calculator free?
Yes. Our percentage calculator is completely free and unlimited. No sign-up, no registration, no hidden fees. Use it as many times as you want.
Is my data safe?
Yes. All calculations happen locally in your browser. No data is sent to any server. Your numbers are never stored, shared, or transmitted.
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