Exponential Decay
Enter your known values, leave one input blank, and solves for the missing one. Try different units for next level excitement!
Learning zone
Exponential decay is growth's mirror: losing a fixed percentage each period multiplies the amount by (1 − r) every step. A car depreciating 20% per year keeps 0.8 of its value annually — a $30,000 car is worth 30000 × 0.8⁵ ≈ $9,830 after five years. The same shape governs cooling coffee, drug concentrations between doses, and fading chlorine residual in a treated tank; enter r as a decimal (20% → 0.20).
Exponential Decay
Where
- = Final amount
- = Initial amount
- = Decay rate per period (decimal)
- = Number of periods
Missing one of these? Work it out first, then come back
- Final amount — Exponential Growth, Exponential Growth by Doubling Time
- Initial amount — Exponential Growth, Exponential Growth by Doubling Time
- Decay rate per period (decimal) — Exponential Growth, Simple Interest
- Number of periods — Exponential Growth, Simple Interest