Exponential decay calculator

Project repeated proportional loss with remaining = initial × (1 − loss rate)ⁿ.

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Starting quantity

Loss per period (%)

More inputs and assumptions

Number of periods

Answer

…

Project repeated proportional loss with remaining = initial × (1 − loss rate)ⁿ.

More results

Precision and calculation record

Decimal places in numeric results and text downloads

Rounding changes displayed numbers, not the calculation. Text, fractions, matrices and CSV schedules keep their own formatting. Automatic keeps up to 12 significant digits, with money shown to cents where applicable.

Saved scenario

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Formula and assumptions

Loss is a percentage of the remaining quantity each period. Zero elapsed periods keep the starting quantity, including a 100% loss setting. This is not a linear decrease.

Automatic precision shows numbers to 12 significant digits. Thousands separators such as 1,000 are accepted; use a dot for decimals.

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Updated 2026-09-26

Using Exponential decay calculator

Project repeated proportional loss with remaining = initial × (1 − loss rate)ⁿ.

Loss is a percentage of the remaining quantity each period. Zero elapsed periods keep the starting quantity, including a 100% loss setting. This is not a linear decrease.

Next: Half life calculator

A worked example

Example inputs: starting quantity = 100, loss per period (%) = 20, number of periods = 2. Remaining quantity = 64.

Before you use the result

Loss is a percentage of the remaining quantity each period. Zero elapsed periods keep the starting quantity, including a 100% loss setting. This is not a linear decrease.

Example results for starting quantity

These examples use Loss per period (%): 20; Number of periods: 2. They are reference calculations, not recommended settings.

Starting quantity	Remaining quantity
50	32
100	64
200	128

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