How is Payback calculated?
With uniform flows (this calculator), Payback is simply the initial investment divided by the annual flow. With variable flows, it's computed year by year until accumulated cash turns positive, interpolating within the crossover year.
For non-uniform flows: the year where accumulated cash stops being negative, with linear interpolation within that year.
Worked example
A bakery needs $80,000 of initial investment (oven, counter, working capital). It projects a net flow of $32,000 per year.
Payback = $80,000 / $32,000 = 2.5 years
Meaning that in 2 years and 6 months the owner recovers the initial investment. From that point on, every dollar of flow is net profit on top of the investment.
Risk bucket: < 3 years → low. For a bakery in a stable market, it's an excellent payback.
3 common mistakes when using Payback
1.Using it as the only decision metric
Payback ignores everything that happens after recovering the investment. A project with a 4-year payback and huge flows after may be better than one with a 2-year payback and small flows. Always pair it with NPV.
2.Not discounting flows
This calculator shows the simple payback. Discounted payback, which applies the MARR to each flow before accumulating, is always longer and more realistic. For rigorous analysis use the full dashboard.
3.Ignoring inflation in 5+ year projects
A 6-year payback in a country with 30% annual inflation is radically different from 6 years in one with 3%. The recovered money has different purchasing power than the invested money — something simple payback doesn't capture.
Frequently asked questions
- Depends on sector and risk. As a Latam benchmark: < 3 years is low risk, 3–5 years acceptable, > 5 years only if NPV is very positive. Volatile sectors (food service, e-commerce) should aim for < 3 years.