Payback period

Before you rely on it

What to check

Never rank projects on it alone.

The common error

Where people go wrong with payback period

Choosing a two-year payback over a three-year one when the three-year project earns for a decade afterwards. Payback cannot see that, and it will pick the worse project every time the pattern repeats.

Worked through

Payback period in plain numbers

A machine costs $30,000 and saves $8,000 a year. Cumulative savings reach $30,000 after 3.75 years, so the simple payback period is 3.75 years. Now discount the savings at 8%. They are worth $7,407, $6,859, $6,351, $5,881 and $5,445 in years one through five, totaling $26,498 after four years. Add a fraction of the fifth year, (30,000 − 26,498) ÷ 5,445, and the discounted payback is about 4.6 years. Ignoring time value made the project look a year faster. Neither figure says anything about what happens after the money is recovered.

Easily confused

Payback period and its neighbours

Payback period is not the same as return on investment, NPV or IRR. It measures how quickly the investment is recovered; it ignores the size of returns after that point and, in the simple version, ignores the time value of money. NPV and IRR account for all cash flows. Discounted payback improves the simple version by discounting. Break-even is a different concept, the sales volume that covers costs. Payback is best seen as a liquidity and risk screen, not a measure of profitability.

In real decisions

Where payback period turns up

Small businesses and households use it for quick decisions, such as whether solar panels or efficiency upgrades will pay for themselves; managers set maximum payback thresholds for approving projects, especially where risk is high or cash is tight; it is easy to explain to non-financial colleagues. Comparing paybacks across options helps to rank projects when capital is limited. Pair it with NPV to avoid missing long-term value.

Know the edges

Where payback period stops being reliable

A project with a fast payback can be a poor investment if returns end soon after; a slow payback can be an excellent one with long benefits. Estimates of yearly savings or income may be off, and they change over time, and it ignores inflation and taxes in the simple form. Use payback to screen risk, then look at the whole cash flow before deciding.

Quick answers

What people ask about payback period

What is a good payback period? Depends on the investment and your alternatives. Businesses often set a maximum, such as two or three years for equipment. Longer paybacks carry more risk of the assumptions changing.

Why use discounted payback? It counts the time value of money, so distant savings are worth less. It gives a longer, more realistic figure than the simple version.

Does payback show total profit? No. It shows only how long recovery takes. A project can pay back fast and stop earning, or pay back slowly and earn for decades.