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Percentage Increase Calculator
Calculate the percentage change from an initial value to a final value.
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How this calculator works
Calculate growth, markups, or price increases using our free percentage increase calculator. This tool determines the relative growth from an initial starting value to a final ending value. Input your numbers to see the exact percentage change alongside a detailed breakdown of the calculation.
- Method
- Relative increase from a positive baseline
- Source
- U.S. Bureau of Labor Statistics — Calculating percent changes
- Last reviewed
- 2026-08-26
Method limitations
- Starting value must be positive.
- Ending value must not be lower than starting value.
- Values must use the same quantity and unit.
- The result measures relative arithmetic change, not causation or profitability.
Engine-backed example
Percentage increase from a positive baseline: worked example
What is the percentage increase from 80 to 100?
- Starting value
- 80
- Ending value
- 100
Percentage Increase25.00%
- Absolute Difference
- 20
- Starting Value
- 80
- Ending Value
- 100
The absolute increase is 20. Dividing 20 by the starting value, 80, and multiplying by 100 gives a 25% increase.
Trust and review
Who created and reviewed this calculator?
- Author
- CalcOS Editorial TeamResponsible for percentage-change terminology, examples, assumptions, and search-intent clarity.
- Reviewed by
- CalcOS Scientific ReviewTechnical review of percentage-increase arithmetic, positive-baseline requirements, boundaries, rounding, engine parity, and interpretation.
- Substantive review date
- 2026-08-26Positive starting values, non-decreasing ending values, absolute increase, percentage increase, invalid-state handling, worked-example parity, and stated limitations.
Sources
- U.S. Bureau of Labor Statistics — Calculating percent changes
- U.S. Bureau of Labor Statistics — Index Numbers and Percent Changes
Assumptions used by this calculator
- The starting and ending values measure the same quantity in the same units.
- The starting value is finite and strictly greater than zero.
- The ending value is finite and is not lower than the starting value.
- Percentage increase equals (ending value − starting value) divided by starting value, multiplied by 100.
- The result describes relative arithmetic change; it does not establish causation, profitability, or investment performance.
- Use a decrease or general percentage-change method when the ending value is lower or when the baseline is zero or negative.