What does this calculator calculate?
Find B% of A, A as a percentage of B, or the percentage change from A to B. Choose the calculation type and enter two values.
Worked examples
These examples use fixed sample inputs, separately from your current calculation. Displayed numbers are rounded.
South Korea units
- Calculation type
- What is B% of A?
- Value A
- 200
- Value B
- 15
- Result
- 30
US units
- Calculation type
- What is B% of A?
- Value A
- 200
- Value B
- 15
- Result
- 30
Frequently asked questions
What is 15% of 200?
200 × 15 ÷ 100 = 30. Select B% of A, then enter A=200 and B=15.
What if the starting value for percentage change is zero?
Percentage change is undefined when A is zero. For a negative base, this calculator uses (B−A) ÷ |A| × 100; interpret that convention carefully.
Method and references
The displayed mathematical formula and input conditions apply. Results are rounded for display after internal calculation; check the assumptions for your use case.
Calculation methods, precision and data storage
Content updated: