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Comparison · Break-Even

Payback Period vs ROI: Which to Use and When

Payback period and ROI compared on two investments of the same size: what each measure rewards, why they can rank the same options in opposite order and how to use them together.

By PriceAndProfit Editorial Updated

Speed vs size Short answer

payback tells you how quickly the cash comes back; ROI tells you how much comes back in total compared with what you put in

Both measures start from the same numbers — the amount invested and the net cash it brings in — and both are undiscounted, so neither needs an interest rate. They differ in what they ignore. Payback stops counting at the moment the investment is recovered, so everything after that is invisible to it. Simple ROI adds up every year in the period but does not care when the money arrives. Used alone, each can point to the wrong project.

Payback period and ROI compared
Payback periodSimple ROI
Formula Years until cumulative net cash flow equals the investment (Total net return − Investment) ÷ Investment
Unit Years or months Percent for the whole period
Counts cash after recovery? No Yes, to the end of the chosen period
Counts timing? Only up to the recovery point No
Best question it answers How long is my cash at risk? How much does each dollar return in total?

Two projects, opposite rankings

Both hypothetical projects cost $20,000 and are judged over five years. Project A front-loads its cash and then fades; Project B starts slowly and keeps paying.

Two hypothetical $20,000 projects
Project AProject B
Net cash flow, years 1–5 $10,000; $10,000; $2,000; $0; $0 $4,000; $6,000; $8,000; $9,000; $9,000
Cumulative after year 2 $20,000 $10,000
Payback period 2.00 years 3.22 years
Total over 5 years $22,000 $36,000
Simple ROI over 5 years 10% 80%

Project A recovers its cost in exactly two years; Project B needs three full years ($18,000) plus $2,000 ÷ $9,000 = 0.22 of the fourth. By payback, A wins clearly. By ROI, B returns $16,000 on top of its cost against A's $2,000. Which one is right depends on the business: if the $20,000 is a large share of your cash and the future of the product line is uncertain, A's speed may be worth more; if cash is comfortable and the five-year cash flows are credible, B creates far more value.

Payback period

  • Use it for: Screening options when cash is tight or the forecast gets less reliable the further out it goes.
  • Watch out for: It rewards quick but small projects and says nothing about profit after recovery.

Simple ROI

  • Use it for: Comparing the total return of options with the same period and the same cost boundary.
  • Watch out for: A long period inflates it; a five-year ROI and a one-year ROI are not comparable.
Bottom line

Use payback as a cash-risk filter and ROI to rank the options that pass it — over the same period, from the same cash flow estimates.

Where the accounting rate of return fits

Managerial accounting texts add a third undiscounted measure, the accounting rate of return: incremental net income divided by the initial investment less its salvage value. It uses accounting income, after depreciation, rather than cash, so it can differ from both payback and a cash-based ROI. All three share the same blind spot — a dollar in year five counts as much as a dollar today. Discounted methods correct for that but need a discount rate, which belongs to financing decisions and is outside this site.

Method reference: OpenStax: Payback and Accounting Rate of Return. Checked October 26, 2026. Projects are hypothetical. Estimates for planning; not tax, legal or financial advice.

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