Percentage Calculator
Solve percentage problems with instant, accurate calculations
Calculation Type
Percentage Made Simple
Choose your calculation type, enter your numbers, and get instant accurate results. Perfect for discounts, tips, taxes, and more!
What is a Percentage Calculator?
A percentage calculator is a tool that solves common percentage problems: finding what X% of a number is, finding what percentage one number is of another, or applying a percentage increase or decrease. It is useful for discounts, tips, taxes, grades, and everyday math.
Our calculator runs in your browser and gives instant results. You enter the numbers and the operation you need (e.g. "20% of 80" or "50 is what % of 200"), and the tool shows the answer. No account or installation required.
How It Works
Percent means "per hundred." So 20% is 20/100, or 0.20. The main operations are:
- What is X% of Y? Answer: (X ÷ 100) × Y. Example: 20% of 80 = 0.20 × 80 = 16.
- X is what percent of Y? Answer: (X ÷ Y) × 100. Example: 25 is what % of 200? (25 ÷ 200) × 100 = 12.5%.
- Increase or decrease: Add or subtract a percentage of a value. E.g. 80 + 15% = 80 + (0.15 × 80) = 92; 80 − 20% = 80 − 16 = 64.
The tool typically has fields for the percentage and the number(s), and may offer presets like "add %" or "subtract %" for quick calculations.
Understanding the Results
The "result" is the computed number or percentage. For example:
- If you ask "What is 20% of 80?" the result is 16.
- If you ask "50 is what % of 200?" the result is 25%.
- If you add 10% to 100, the result is 110.
There is no "average score"—each calculation is independent. Double-check inputs (e.g. 15% vs 1.5%) to avoid mistakes.
Benefits of Using Our Percentage Calculator
- Instant: Get answers as soon as you enter the numbers.
- Private: All calculations run in your browser; we don't see or store your data.
- Multiple modes: Handle "X% of Y," "X is what % of Y," and add/subtract percent in one place.
- Free: No sign-up or limit on use.
- Mobile-friendly: Use on phone or tablet for tips and shopping.
Improvement Tips
- For discounts: enter the original price and the discount % to see the final price (or use "subtract X%").
- For tips: find 15%, 18%, or 20% of the bill, or add that percentage to the total.
- For grades: use "X is what % of Y" when Y is the total points and X is the score.
- Combine with our BMI calculator if you are tracking weight change as a percentage, or use our random number tool for games and draws.
Frequently Asked Questions
Is the percentage calculator free?
Yes. The tool is free to use with no registration.
Do you store my numbers?
No. All calculations are done in your browser. We don't collect or store your inputs or results.
Can I calculate percentage change?
Percentage change is (new − old) ÷ old × 100. If the tool has a dedicated mode for that, use it; otherwise you can compute the difference and then "X is what % of old" for the change.
Why did my result look wrong?
Check that you entered the percentage as a number (e.g. 20 for 20%, not 0.20) if that is what the tool expects. Also confirm which value is the base (e.g. 20% of 80 vs 80% of 20).