Calculate with Percentage
Your result will appear here.
Formula and variables
- r
- the percentage rate
- V
- the whole or reference value
- P
- the resulting part
Percent means per hundred, so a percentage rate is divided by 100 before it is multiplied by the reference value.
Domain note: The comparison whole cannot be zero. Percentage change also requires a nonzero original value.
How to use this calculator
- 1
Choose the percentage question you want to answer.
- 2
Enter the two labeled values.
- 3
Press Calculate percentage.
- 4
Read the result and the generated relationship statement.
A complete example
Problem: What is 18% of 250?
Substitution: (18 ÷ 100) × 250
Result: 0.18 × 250 = 45
Eighteen percent of 250 is 45.
Understand the result
A negative percentage change means a decrease; a positive percentage change means an increase. The displayed magnitude includes that direction label.
Common mistakes
- Dividing by the part instead of the whole.
- Using zero as the original value for percentage change.
- Confusing percentage points with percent change.
Frequently asked questions
What does percent mean?
Percent means per one hundred. For example, 18% equals 18/100, or 0.18.
Can a percentage be greater than 100%?
Yes. A percentage over 100% represents more than one complete whole.
How is percentage change calculated?
Subtract the original value from the new value, divide by the absolute original value, then multiply by 100.