Free Online Percentage Calculator
This percentage calculator handles the five most common percent problems instantly, right in your browser — nothing is uploaded, stored, or shared. Whether you need a percent of a number, a percentage change, or a discount, it's calculated locally and accurately.
How to Calculate Percentages
What is X% of Y? Multiply Y by X and divide by 100, e.g. 15% of 200 = 200 × 0.15 = 30. X is what % of Y? Divide X by Y and multiply by 100, e.g. 30 is 15% of 200. Percent change measures the increase or decrease from an old value to a new one as a percentage. Add or subtract percent applies a percentage markup or discount to a base number.
Percentage Change Formula
Percent change = (new value − old value) ÷ old value × 100. A positive result is an increase, a negative result is a decrease. For example, if a price rises from $50 to $60, that's (60−50) ÷ 50 × 100 = 20% increase.
Percentage Calculator FAQ
How do I calculate a percentage of a number? Multiply the number by the percent divided by 100. What is 10% of 50? 5. How do I find what percent one number is of another? Divide the first by the second and multiply by 100. Does this store my data? No — everything runs in your browser only.