Percentage Calculator
Calculate percentages instantly for discounts, taxes, grades, and more. Free online tool with step-by-step explanations.
How to Use This Calculator
- 1Select the type of percentage calculation you need from the three options.
- 2Enter the first number in the top input field.
- 3Enter the second number in the bottom input field.
- 4Click "Calculate" to see the result and step-by-step explanation.
Common Use Cases
- Shopping: Calculate discounts (20% off $80)
- Restaurants: Figure out tips (15% of $60)
- Taxes: Calculate sales tax (8% of $100)
- Grades: Convert scores (45/50 = what %?)
The Formula Behind
This calculator uses the three fundamental percentage formulas:
- • Find X% of Y: (X ÷ 100) × Y
- • X is Y% of what: X ÷ (Y ÷ 100)
- • What % is X of Y: (X ÷ Y) × 100
Learn the Math Behind Percentages
Understanding how percentage calculations work is essential for everyday life. Whether you are calculating a discount at your favorite store, determining how much to tip at a restaurant, or analyzing data for work, percentages are everywhere.
Why Percentages Matter
Percentages provide a standardized way to express parts of a whole. By converting everything to a base of 100, we can easily compare different quantities. For example, saying you scored 85% on a test immediately tells others that you got 85 out of 100 points, regardless of the actual total number of questions.
Common Mistakes to Avoid
- Always convert percentages to decimals by dividing by 100 before calculating
- Remember that percentage increases and decreases are not symmetric (20% up then 20% down does not equal the original)
- Double-check which value is the "part" and which is the "whole" in your calculation
Want to Learn More?
Read our comprehensive guide to master percentage calculations with detailed examples and formulas.
Frequently Asked Questions
How do I calculate 20% of a number?
Multiply the number by 0.20. For example, 20% of 50 = 50 × 0.20 = 10. You can also divide the number by 5 (since 20% = 1/5).
Is this calculator free to use?
Yes, our percentage calculator is completely free to use. No registration required. We believe everyone should have access to accurate calculation tools.
Can I use this for business calculations?
Absolutely! This calculator is suitable for personal, educational, and business use. Use it for calculating profit margins, tax amounts, discounts, and more.
How accurate is this calculator?
Our calculator provides results accurate to 2 decimal places, which is sufficient for most everyday calculations. For financial or scientific calculations requiring higher precision, consider using specialized software.