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Payback Period Calculator
How long until an investment earns its cost back? Feed uneven cash flows into this payback period calculator and get both the simple and discounted payback, with the break-even point drawn on a cumulative cash-flow chart — the core screen of capital budgeting.
See how this works on three capital-budgeting projects — 3 real examples
Simple payback period
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Discounted payback
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Total cash inflows
$0
Net over horizon
$0
Cumulative cash flow & break-even
The line climbs from −(initial investment) as inflows arrive; payback is where it crosses zero.
Year-by-year cumulative breakdownCash inflows, present values and running totals
| Year | Cash inflow | Cumulative | Discounted inflow | Cumulative (disc.) |
|---|
How your payback period is calculated
The simple payback period accumulates each year’s cash inflow until the running total first reaches the initial investment, then interpolates within the recovery year:
Payback = N + (Cost − CumulativeN) / CFN+1
where N is the last full year before the cumulative inflows cover the cost, CumulativeN is the total recovered by then, and CFN+1 is the inflow during the recovery year. The fractional part assumes cash arrives evenly through the year. This is the standard capital-budgeting payback formula and it works for even or uneven cash flows.
The discounted payback period repeats the process on the present value of each inflow, PVt = CFt / (1 + r)t, where r is the discount rate you set. Because discounting shrinks later cash flows, the discounted running total rises more slowly and the discounted payback is always at least as long as the simple one. If the cumulative total — simple or discounted — never reaches the cost over the years you entered, the payback is undefined and this tool says so plainly rather than inventing a number.
One honest caveat: payback is a liquidity and risk measure, not a profitability one. It ignores every dollar that arrives after break-even, so a project with a fast payback can still be worth less than a slower one. Pair it with net present value or IRR before making the call.
Three projects, one question: when is it repaid?
Two $100,000 cash-flow schedules against a $50,000 cost — then the same inflows against a cost they can never catch.
The default: $50,000 back in under 3 years
simple payback2.85 yrs
- Inflows of $15,000, $18,000 and $20,000 clear the $50,000 line partway through year three.
- Discounting at 10% pushes break-even out to 3.43 years — later money counts for less.
- By year five the project has returned $100,000, twice its cost.
Payback measures speed of recovery, not profit — this project happens to offer both.
Load this example (opens in a new tab)Same $100,000 total, slower start
simple payback3.5 yrs
- Starting at $5,000 and building to $35,000 delays recovery by about eight months.
- Break-even lands exactly halfway through year four, at the midpoint of a $30,000 year.
- Discounted at 10%, the wait stretches to 4.08 years.
The totals match the first tab; the early years are what payback actually grades.
Load this example (opens in a new tab)A $120,000 cost the flows cannot catch
paybackNever
- Five years of the steady schedule bring back $100,000 — $20,000 short of the cost.
- No amount of patience helps at 10%: the discounted recovery stops at $74,088.
- The calculator reports no payback rather than pretending one exists.
A payback that never arrives is the clearest verdict capital budgeting can give.
Load this example (opens in a new tab)Illustrations only, not financial advice. Your own rate, taxes and insurance will differ — check with a qualified financial advisor before acting on any of this.
Reading a payback period, in plain English
- ▸Payback answers “when do I get my money back?” — the point where cumulative inflows equal the upfront cost, shown as the zero crossing on the chart above.
- ▸Uneven cash flows are the norm. Real projects ramp up or taper off, so enter each year separately rather than assuming a flat annuity.
- ▸Discounted payback is the honest version. Turn the discount rate up to your cost of capital and watch the break-even slide later — that gap is the time value of money.
- ▸Shorter payback means less time at risk, which is why lenders and boards like it, but it says nothing about total profit.
- ▸Use it as a screen, not a verdict. Compare the payback against NPV and IRR before committing capital.
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Frequently asked questions
What is the payback period?
The payback period is the time it takes for an investment’s cumulative cash inflows to recover its initial cost. If a $50,000 project returns $15,000, $18,000 and $20,000 in its first three years, the cumulative inflows hit $50,000 partway through year three, so the payback period is about 2.9 years.
How do you calculate the payback period with uneven cash flows?
Accumulate each year’s cash flow until the running total reaches the initial investment, then interpolate within the final year. The formula is: full years before recovery + (unrecovered cost ÷ the cash flow in the recovery year). This calculator does that automatically for any uneven cash-flow schedule you enter.
What is the discounted payback period?
The discounted payback period uses the present value of each cash flow instead of its face value, so it accounts for the time value of money. Each inflow is divided by (1 + discount rate)^year before it is accumulated, which is why the discounted payback is always at least as long as the simple payback.
Why is the discounted payback period longer than the simple one?
Discounting shrinks every future cash flow — a dollar five years out is worth less than a dollar next year — so it takes more time for the discounted running total to reach the initial cost. At a 10% discount rate, a project that pays back in 2.9 simple years might take 3.4 discounted years.
What are the limitations of the payback period in capital budgeting?
The simple payback period ignores the time value of money and every cash flow after the break-even point, so it can favor projects that recover fast but earn little overall. Use it as a liquidity and risk screen alongside NPV and IRR rather than as the only decision rule — the discounted payback fixes the first flaw but not the second.
What counts as a good payback period?
Shorter is generally better because the capital is at risk for less time, but an acceptable length depends entirely on the industry and the project’s expected life. A retail fit-out might need to pay back in under two years, while infrastructure or energy projects routinely accept paybacks of seven years or more.
What if the cash flows never recover the investment?
If the cumulative inflows never reach the initial cost over the years you entered, the payback period is undefined (effectively infinite). This calculator flags that case clearly instead of showing a misleading number — it usually means the project is a loss over the horizon modeled, or that more years of cash flow need to be added.
Disclaimer: these calculators are educational tools, not financial advice. They model your inputs with published formulas, but they cannot know your full situation — for decisions with real stakes, talk to a qualified professional. Formulas and defaults last reviewed .