Exponential Decay Calculator
Find how much of a starting quantity remains after repeated percentage losses. Enter an initial value, a decay rate per period, and the number of periods; the tool returns the final value and the total amount lost. Free, runs in your browser, no sign-up.
What this calculator does
The Exponential Decay Calculator estimates your result instantly from the values you enter, using standard math & conversions formulas. Find how much of a starting quantity remains after repeated percentage losses. Enter an initial value, a decay rate per period, and the number of periods; the tool returns the final value and the total amount lost. Free, runs in your browser, no sign-up. Calculations run in your browser, so nothing you type is sent to a server, and the output is an estimate rather than a certified or official figure.
Result
About Exponential Decay Calculator
The Exponential Decay Calculator applies the formula A = P(1 − r)t, where P is the initial value, r is the decay rate written as a decimal, and t is the number of periods. It reports the final value alongside the total amount that has decayed away.
The decay rate is entered as a percentage per period and must fall between 0 and 100%. Results are rounded to four decimal places.
Formula & Mathematical Calculation
Final Value = f(Initial Value, Decay Rate (% per period), Number of Periods)
Calculated according to standard math formulas implemented in the calculator core.
Calculation Example
Suppose the initial value is 1000, the decay rate is 5% per period, and there are 10 periods. Converting the rate to 0.05, the final value is 1000 × (1 − 0.05)10 = 1000 × 0.9510 = 598.7369. The total decay is 1000 − 598.7369 = 401.2631.
Key Benefits
- Shows both the remaining final value and the total amount lost in one step.
- Accepts any decay rate from 0% to 100% per period and any number of periods.
- Works for any repeated-percentage decline, such as depreciation or radioactive-style loss, without a spreadsheet.
- Runs entirely in the browser with no sign-up.
How to Use this Calculator
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Enter the initial value
Type the starting quantity into the Initial Value field. -
Set the decay rate
Enter the loss per period as a percentage in the Decay Rate (% per period) field, between 0 and 100. -
Enter the number of periods
Type how many periods the decay runs for in the Number of Periods field. -
Calculate
Press Calculate to see the Final Value and Total Decay.
Assumptions & Limitations
What the calculation assumes
- Every value you enter is treated as an exact, known amount.
- Any rate or interval you enter is assumed to hold for the whole period unless the form asks for it separately.
- Results use standard published formulas and account only for the values entered above.
- Rounding is applied for display; the underlying calculation uses your full precision.
- Results are returned in the same units you enter, unless the tool states the output unit.
What it does not cover
- Exponential Decay Calculator produces a calculated result for reference and learning, not a certified or official measurement.
- Real-world outcomes differ when tolerances, rounding rules or local standards apply.
- Definitions and standards vary by region and change over time; verify the convention that applies to your case.
- Figures are only as accurate as the inputs you supply — check them before acting on the result.
- For work where the result carries real consequences, confirm it against an authoritative source.
Frequently Asked Questions
Free to use, no account needed. Calculations run in your browser, so nothing you type is sent to a server. Results are estimates — how we build and check our calculators.