Measure percentage change between an initial value and a final value — the standard growth or decline rate.
Formula
change % = ((final − initial) ÷ initial) × 100
Positive results indicate increase; negative results indicate decrease. Example: from 80 to 100 → +25%; from 200 to 150 → −25%.
When to use it
Report revenue deltas, stock price moves, weight-tracking trends, or year-over-year KPIs in dashboards and slide decks.
Limitations
Initial value cannot be zero — percent change from zero is undefined. Very small denominators inflate percentages dramatically. The formula is symmetric in math but not in perception (a 50% drop requires a 100% gain to recover).