Discounted Payback Period Calculator

Estimate discounted payback period using a discount rate (and compare to simple payback).

Discounted payback answers: how long until the present value of cash flows pays back the initial investment-

It is stricter than simple payback because it accounts for the time value of money via a discount rate (required return / MARR).

Prefer an explanation- Read the guide.
 
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Tip: you can type commas (e.g., 10,000).

Example

Using the default inputs, the result is:
54.3 months
Initial investment (upfront)
$100,000
Annual cash flow
$30,000
Max years to evaluate
10
Discount rate
12%

How to calculate

  1. Enter the initial investment (upfront cash outflow).
  2. Enter annual cash flow, a discount rate, and a max evaluation horizon.
  3. Review discounted payback vs simple payback (undiscounted).
  4. If discounted payback is not reached, the project may still have positive NPV depending on the horizon and discount rate.

Formula

Discounted payback is the earliest time where cumulative discounted cash flows >= initial investment
  • Cash flows occur at the end of each year (discounted by year index).
  • Uses a constant annual cash flow for simplicity.

Benchmarks

  • Discounted payback is typically longer than simple payback because future cash flows are worth less today.
  • Use discounted payback for risk management; use NPV to measure value created at the hurdle rate.
  • If payback depends heavily on late-year cash flows, results are sensitive to discount rate and execution risk.

FAQ

Why is discounted payback longer than simple payback-
Discounting reduces the present value of future cash flows, so it usually takes longer (in discounted terms) to recover the initial investment.

Common mistakes

  • Using a discount rate that does not match the risk of the cash flows (too low overstates value).
  • Mixing nominal cash flows with a real discount rate (inflation mismatch).
  • Treating payback as the only decision rule (NPV and strategic value still matter).

Quick checks

  • Use consistent time units (monthly vs annual) when entering rates and cash flows.
  • Run a sensitivity check on the input that drives the result most (often discount rate or growth).
  • Treat the output as a decision aid, not a prediction; validate assumptions with reality.