Simple Payback Period Calculator
The payback period is the simplest way to gauge how quickly an investment pays for itself. It answers a single question: how long until the cash the project generates equals the money you put in? With steady annual cash inflows, the answer is just the initial investment divided by the annual inflow. This calculator returns the payback period in decimal years and as a years-and-months breakdown, plus the annual return rate implied by the cash flows. All money figures are in US dollars. Payback is a useful risk screen but ignores the time value of money.
Payback period formula
Payback period (years) = initial investment / annual net cash inflow
Whole years = floor (payback period)
Months = (payback period - whole years) * 12
Simple annual return = annual net cash inflow / initial investment * 100
The simple annual return is the reciprocal of the payback period expressed as a percentage. A 4-year payback implies a 25% simple annual return on the outlay, before considering the time value of money.
Using the payback period
- This method assumes equal annual cash inflows; uneven flows need a cumulative approach.
- Shorter payback means faster capital recovery and generally lower risk.
- Payback ignores cash flows after the recovery point and the time value of money.
- Pair it with net present value or internal rate of return for a fuller picture.
- Enter your own project figures; the tool stores no preset data.
Payback period: frequently asked questions
What is the payback period?
The payback period is the time it takes for an investment to recover its initial cost from the cash it generates. With even annual cash flows, it equals the initial investment divided by the annual cash inflow. A shorter payback means the outlay is recouped faster.
How is simple payback period calculated?
Simple payback period = initial investment / annual net cash inflow. If a project costs US$50,000 and returns US$12,500 of net cash each year, the payback period is 4.0 years. This method assumes steady, equal annual cash flows.
What are the limits of the payback method?
Simple payback ignores the time value of money and any cash flows after the payback point. It does not measure overall profitability. It is best used as a quick liquidity and risk screen, alongside discounted measures such as net present value and internal rate of return.
What is a good payback period?
It depends on the project and the company's required threshold. Shorter is generally lower risk because the capital is recovered sooner. Many firms set a maximum acceptable payback; projects beyond that are rejected. Compare the result to your own hurdle.
How is the payback period shown in months?
The whole-year part is the integer number of full years, and the fractional year is converted to months by multiplying by 12. A payback of 4.25 years is 4 years and 3 months. This calculator shows both the decimal years and the years-and-months breakdown.
Official sources
- U.S. Small Business Administration, business planning resources: sba.gov.
- Investor.gov, investing basics glossary: investor.gov.
Reviewed by the CalculatorHub team, edited by James Graham, 17 June 2026. See our methodology.