Quickly calculate percentages: what is X% of Y, what percent is X of Y, and percentage increase or decrease. Essential for discounts, grades, stats, and business math.
Percentage Calculator
How to Use
- Choose the mode (X% of Y, X is what % of Y, or % change).
- Enter the values.
- Click Calculate.
Formula
X% of Y = (X/100)×Y. Percent = (X/Y)×100. % change = ((new−old)/old)×100.
Worked Example
Example: 15% of 80 = 12. 25 is 50% of 50. Increase from 40 to 50 is 25%.
What the Result Means
Use results for sale prices, test scores, growth rates, and comparisons.
Important Notes & Limitations
- Division by zero is invalid—Y or old value must not be zero.
Frequently Asked Questions
How do I calculate a discount?
Use X% of Y for the discount amount, then subtract from the original price—or use the Discount Calculator.
Does order matter for % change?
Yes. Always (new − old) / old.
Can I use decimals?
Yes. Enter decimal values as needed.
Is this the same as percentage points?
No. A change from 10% to 12% is 2 percentage points, or a 20% relative increase.
Related Calculators
See also: Loan EMI, Mortgage, Compound Interest, Percentage.
Disclaimer: Results are approximate and for educational and informational purposes only. They are not financial, tax, medical, or legal advice. Verify important decisions with a qualified professional.