Percentage Calculator
Use this free online tool to get instant results. Fast, secure, and easy to use.
How to Use Percentage Calculator
1
Select Calculation Type
Choose from: What is X% of Y? X is what percent of Y? or Percentage increase/decrease.
2
Enter Your Values
Input the numbers in the provided fields. Use decimal points for precision (e.g., 12.5).
3
Get Instant Result
Answer appears automatically as you type. No need to click calculate button.
4
Copy or Calculate Again
Use the result in your work, or adjust numbers for different scenarios instantly.
📐 Common Percentage Formulas
- Find X% of Y:
Y × (X/100)- What is 20% of 150? → 150 × 0.20 = 30 - X is what % of Y:
(X/Y) × 100- 30 is what % of 150? → (30/150) × 100 = 20% - % Increase:
((New-Old)/Old) × 100- Price rose from $50 to $60 → 20% increase
Frequently Asked Questions
How do I calculate percentage increase?
Subtract original from new, divide by original, multiply by 100. Example: $50 to $70 → (70-50)/50 × 100 = 40% increase. Our tool does this automatically.
Can I calculate what percentage one number is of another?
Yes! Use "X is what percent of Y" mode. Enter the part in X and whole in Y. Example: 25 is what % of 200? Answer: 12.5%
Does it handle negative percentages?
Yes! Negative results indicate decrease or loss. -15% means 15% decrease. Useful for calculating losses, discounts, or negative growth.
How to add percentage to a number (tax, tip)?
Use "What is X% of Y" to find the amount, then add to original. Or use our GST/Tip calculator for automatic total calculation including percentage.
Is there a limit on number size?
Handles up to 15-digit numbers accurately. For very large numbers (trillions+), results may show in scientific notation but remain precise.