CALCULATOR
Percentage Change Calculator
Percentage Change. Example: Original quantity: 80, New quantity: 100 gives 25 %. Find the signed relative change from a positive original value. A negative answer means decrease. Zero original has no defined relative percentage; original minimum is 1 to ensure the complete accepted domain is safe.
How the calculation works
100 × ((new − old) / old)
Worked example
With original quantity 1 units, new quantity 1 units, percentage result is 0 %.
Assumptions and limits
Find the signed relative change from a positive original value. A negative answer means decrease. Zero original has no defined relative percentage; original minimum is 1 to ensure the complete accepted domain is safe.