Percentage Calculator
Calculate percentages, increases, and decreases
What does this calculator do?
Answer common percentage questions on one page: a percentage of a value, relative change, percentage difference, reverse calculations, and percentage points.
Inputs
- Two numbers whose meaning depends on the selected mode
- A direction for increase/decrease modes
Outputs
- The primary value or percentage
- Absolute change, direction, substituted formula, and explanation where relevant
Formula and method
The selected formula is applied directly to the supplied values. Relative change uses the magnitude of the starting value; percentage-point mode subtracts rates directly.
Worked example
15% of 240 = (15 / 100) × 240 = 36. A change from 240 to 276 is 15%.
How to interpret the result
Percentage change answers a relative question. Percentage points compare two rates directly, so 18% versus 12% is a difference of 6 percentage points.
Common mistakes
- Confusing percentage points with percentage change
- Using zero as a relative-change baseline
- Reversing a discount by subtracting the discount instead of dividing by the remaining factor
Assumptions
- Values are treated as ordinary real numbers
- Negative values are allowed when the selected formula remains meaningful
Limitations
- A relative percentage from zero is undefined
- Rounding is applied only to display, not to the calculation
Frequently asked questions
What is 17% of 480?
17 / 100 × 480 = 81.6.
What is the difference between percentage points and percent change?
Percentage points subtract two rates directly; percent change divides the change by a baseline.
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