Percentage Calculator
Calculate percentages instantly with our free online percentage calculator. Find what percent one number is of another, calculate percentage increase or decrease, figure out tips and discounts, and solve all your percentage problems in seconds. Trusted by over 50 million users worldwide.
How to Calculate a Percentage (3 Easy Steps)
Quick Formula: Percentage of a number = (Percentage ÷ 100) × Number
- Divide the percentage by 100 to convert to decimal
- Multiply the decimal by your number
- Get your answer!
Step 1: 25 ÷ 100 = 0.25
Step 2: 0.25 × 200 = 50
✓ Answer: 25% of 200 = 50
💡 Quick Examples
💡 Quick Examples
💡 Quick Examples
💡 Quick Examples
🔍 Quick Answers to Common Percentage Questions
How do I calculate 20% of a number?
To calculate 20% of any number, multiply the number by 0.20 (or simply divide by 5). Example: 20% of $85 = $85 × 0.20 = $17. Quick trick: Find 10% by moving the decimal left, then double it.
How much is a 15% tip on $50?
A 15% tip on $50 is $7.50. Calculation: $50 × 0.15 = $7.50. Your total bill with tip would be $50 + $7.50 = $57.50. For 20%, it would be $50 × 0.20 = $10 tip.
How do I calculate percentage increase?
Use this formula: ((New Value − Old Value) ÷ Old Value) × 100. Example: If a price went from $80 to $100: ((100 − 80) ÷ 80) × 100 = 25% increase.
What is the easiest way to calculate percentages mentally?
The 10% method is easiest: Move the decimal point one place left to find 10%, then adjust. Example: For 15% of $80 → 10% = $8, half of that (5%) = $4, so 15% = $8 + $4 = $12.
How do I find what percentage one number is of another?
Divide the part by the whole, then multiply by 100. Formula: (Part ÷ Whole) × 100. Example: 30 is what % of 150? → (30 ÷ 150) × 100 = 20%.
How do I calculate a discount percentage?
To find the sale price: Original Price × (1 − Discount%/100). Example: $120 with 25% off = $120 × 0.75 = $90. You save $30!
📋 Percentage Cheat Sheet (Quick Mental Math)
Memorize these shortcuts to calculate percentages instantly without a calculator:
🌍 Where Percentages Are Used in Real Life
Restaurant Tipping Guide (US)
| Poor service | 10% |
| Average service | 15% |
| Good service | 18% |
| Excellent service | 20% |
| Outstanding | 25%+ |
💡 $75 bill × 20% = $15 tip
Shopping Discounts
| 10% off | Small sale |
| 25% off | Good deal |
| 50% off | Half price |
| 70% off | Clearance |
| BOGO | = 50% off |
💡 $89.99 − 30% = $62.99
US Sales Tax by State
| Oregon, Montana | 0% |
| Colorado | 2.9% |
| Texas | 6.25% |
| California | 7.25% |
| NYC | 8.875% |
💡 $100 + 8.875% = $108.88
Finance & Investing
| Savings APY | 4-5% |
| Stock market avg | ~10%/yr |
| Mortgage rates | 6-7% |
| Credit card APR | 20-30% |
| Inflation target | 2% |
💡 $10,000 × 5% APY = $500/year
📖 How to Use the Percentage Calculator
Our free percentage calculator offers four powerful modes to solve any percentage problem instantly:
1. Basic Percentage — What is X% of Y?
Use this to find a percentage of any number. Perfect for calculating tips, taxes, discounts, or any portion of a whole.
Example: 15% of $80 = (15 ÷ 100) × 80 = $12
💡 Real-World Example: Calculating a 20% Tip
Your restaurant bill is $65. To calculate a 20% tip:
(20 ÷ 100) × 65 = $13 tip
Total with tip: $65 + $13 = $78
2. What Percent — X is what % of Y?
Find what percentage one number represents of another. Great for test scores, sales targets, or comparing values.
Example: 45 is what % of 180? → (45 ÷ 180) × 100 = 25%
💡 Real-World Example: Test Score
You got 42 questions right out of 50:
(42 ÷ 50) × 100 = 84%
3. Increase or Decrease by Percentage
Calculate the final value after adding a markup or applying a discount.
Decrease: New Value = Original × (1 − Percentage/100)
💡 Real-World Example: 30% Off Sale
Original price: $120, Discount: 30%
$120 × (1 − 0.30) = $120 × 0.70 = $84
You save: $36!
4. Percentage Change
Calculate how much something has increased or decreased in percentage terms.
💡 Real-World Example: Salary Increase
Old salary: $52,000, New salary: $58,500
(($58,500 − $52,000) ÷ $52,000) × 100 = +12.5% raise
📊 Complete Percentage Reference Table
Quick reference for frequently used percentages with visual representation:
| Percentage | Decimal | Fraction | Visual | Of $100 | Common Use |
|---|---|---|---|---|---|
| 1% | 0.01 | 1/100 | $1 | Processing fees | |
| 5% | 0.05 | 1/20 | $5 | Small tip | |
| 10% | 0.10 | 1/10 | $10 | Easy mental math | |
| 15% | 0.15 | 3/20 | $15 | Standard tip | |
| 20% | 0.20 | 1/5 | $20 | Good tip, common discount | |
| 25% | 0.25 | 1/4 | $25 | Quarter off sale | |
| 33.33% | 0.333 | 1/3 | $33.33 | Splitting 3 ways | |
| 50% | 0.50 | 1/2 | $50 | Half off, BOGO | |
| 75% | 0.75 | 3/4 | $75 | Clearance sales | |
| 100% | 1.00 | 1/1 | $100 | Full amount |
❓ Frequently Asked Questions
Divide the percentage by 100, then multiply by the number. For example, to find 20% of $50: (20 ÷ 100) × 50 = $10. Or simply use the "Basic %" tab in our calculator above — just enter the percentage and number for instant results.
For a 15% tip, multiply the bill by 0.15. For 20%, multiply by 0.20. Quick trick: For 15%, find 10% (move decimal left) then add half of that. Example: $60 bill → 10% = $6, half = $3, so 15% tip = $9. Use our calculator's "Increase/Decrease" tab for precise calculations.
Divide the smaller number by the larger number and multiply by 100. Example: What percent is 30 of 150? (30 ÷ 150) × 100 = 20%. Use the "X is what % of Y" tab for quick calculations.
Use the formula: ((New Value − Original Value) ÷ Original Value) × 100. If the result is positive, it's an increase; if negative, it's a decrease. Example: Price went from $80 to $100 → ((100 − 80) ÷ 80) × 100 = 25% increase.
To find the sale price after a discount: multiply the original price by (1 − discount percentage as decimal). Example: $80 item with 25% off → $80 × (1 − 0.25) = $80 × 0.75 = $60. Use our "Increase/Decrease" tab with "Discount" selected.
"Percent" is used with a number (like "50 percent"), while "percentage" refers to the concept in general ("what percentage?"). Both mean "per hundred" — the terms are essentially interchangeable in everyday use. The symbol % can be used with either.
On most calculators: Enter the number, press ×, enter the percentage, then press %. For example, to find 15% of 80: type 80 × 15 % = 12. On iPhone/Android calculators, you may need to type 80 × 0.15 = instead.
Yes! Percentages over 100% indicate more than the whole. For example, if sales grew from 100 to 250, that's a 150% increase. Or if you earned 120% of your quota, you exceeded your target by 20%.
Divide by the percentage as a decimal. If $30 is 20% of something, then: $30 ÷ 0.20 = $150. Formula: Original = Part ÷ (Percentage ÷ 100). This is called finding the "base" or "whole" from a percentage.
Yes! This percentage calculator is 100% free with no signup required. Use it unlimited times on any device — desktop, tablet, or mobile. Your calculations are done instantly in your browser with no data stored on our servers.
This calculator and content has been reviewed for mathematical accuracy by our team of educators and math specialists.
Last reviewed and updated: February 15, 2026
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