Why use this calculator
Percentage calculations are used everywhere — from calculating discounts and tax to understanding statistics and financial returns. This versatile calculator handles all common percentage problems.
How to use it
Select the type of percentage calculation you need, enter the two values, and get instant results with the formula shown.
The formula
X% of Y = Y × (X/100). X is what % of Y = (X/Y) × 100. % Change = ((New - Old) / |Old|) × 100.
Worked examples
What is 25% of 200?
50
15 is what percent of 60?
25%
Percentage change from 80 to 100
25% increase
When people use it
- Calculating discounts and sales prices
- Grade calculations
- Financial return percentages
- Statistical analysis
Tips
- Remember: 'of' means multiply in percentage problems
- Percentage change can be negative (a decrease)
- To reverse a percentage: if X is 25% of Y, then Y = X / 0.25
Questions people ask
- How do I calculate a percentage increase?
- Subtract the old value from the new value, divide by the old value, and multiply by 100. Example: from 80 to 100 = (100-80)/80 × 100 = 25% increase.