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Forty thousand recovered at 16,000 a year
A shop spends 40,000 on a machine. The machine is expected to leave 16,000 of extra cash each year after operating cost. 40,000 ÷ 16,000 is 2.5 years.
Project outlay: 25% lower
Change project outlay to 30,000 while keeping the other example values the same.
Project outlay: 25% higher
Change project outlay to 50,000 while keeping the other example values the same.
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Quick answer
What does the Project payback period calculate?
How many years of this annual cash inflow recover the project outlay? This calculator uses project outlay, and annual net cash inflow to estimate years for annual cash to recover the outlay immediately in your browser.
With the values currently entered, the result is 2.5 years — simple payback period. It also shows payback in months, calendar stretch, project outlay, and annual net cash inflow.
How to use the Project payback period
- Replace the example values with your own numbers.
- Review the result and supporting figures as they update automatically.
- Check the formula and assumptions before using the estimate for a decision.
Inputs used
- Project outlay
- Annual net cash inflow
Project payback period formula
Simple payback years = project outlay ÷ annual net cash inflow.
Assumptions
- DOE life-cycle cost guidance defines the payback period as the years just sufficient for initial investment costs to be offset by cumulative annual savings.
- Simple payback does not discount those savings. The annual inflow stays constant. Cash after the payback date is ignored.
Verify the inputs
Authoritative sources
These sources explain the definitions, factors, or rules behind this tool. Their geographic scope is shown because an official source for one country is not automatically valid somewhere else.
Defines the payback period as the years just sufficient for initial investment costs to be offset by cumulative annual savings. Simple payback does not discount those savings.
Internal rate of return in project analysisUS Department of EnergyScope: Federal project financial-analysis methodology; method is generalDefines IRR as the discount rate at which net present value is zero, and reports simple payback as the years for savings to offset the outlay.
Sources do not endorse Calculum. Check the source date, scope, and your own documents before making a financial, tax, insurance, or reporting decision.
Practical guide
Project payback period example and edge cases
Simple payback asks how long a repeating cash inflow takes to recover the outlay. DOE life-cycle cost guidance writes that as the years just sufficient for initial investment costs to be offset by cumulative annual savings. The inflow is not discounted.
Example: Forty thousand recovered at 16,000 a year
A shop spends 40,000 on a machine. The machine is expected to leave 16,000 of extra cash each year after operating cost. 40,000 ÷ 16,000 is 2.5 years.
- Project outlay
- 40,000
- Annual net cash inflow
- 16,000
Calculated result2.5 yearssimple payback period
Payback is 2.5 years, or 30 months. Cash after that date is ignored. If a later dollar is worth less to you than a dollar today, open the project NPV calculator.
Example results use the default display profile. The calculator above follows your selected country and units.
How to read the result
- Read the year count first. Then check months. A shorter payback only means the outlay comes back sooner, not that the project earns more.
- A zero or negative inflow never recovers the outlay. The calculator stops there.
Edge cases worth checking
The inflow is fat in year one and thin later
Simple payback assumes the same cash every year. If year one is a spike, recover the outlay by hand on a year list, or use NPV with a cautious average.
You want the discounted payback
DOE prefers discounted payback because it adjusts later savings for the time value of money. This page is the simple screen. Use project NPV for the discounted leftover.
What changes the result most
Project outlay
Use a current amount for project outlay. Include fees or recurring costs that belong in the same figure.
Annual net cash inflow
Use a current amount for annual net cash inflow. Include fees or recurring costs that belong in the same figure.
Try a different scenario
Small changes show whether the answer is stable or sensitive.
Project outlay: 25% lower
30,0001.9 yearssimple payback period
Project outlay: 25% higher
50,0003.1 yearssimple payback period
Annual net cash inflow: 25% higher
20,0002 yearssimple payback period
Common mistakes
Check project outlay
DOE life-cycle cost guidance defines the payback period as the years just sufficient for initial investment costs to be offset by cumulative annual savings. Make sure this matches the number you enter.
Keep annual net cash inflow consistent
Simple payback does not discount those savings. The annual inflow stays constant. Cash after the payback date is ignored. Use the same units and time period throughout the calculation.
Do not rely on one project payback period scenario
Run a cautious case and an optimistic case. The range is often more useful than one exact-looking number.
Use this result well
How many years of this annual cash inflow recover the project outlay?
It does not replace a quote, contract, accountant, or local employment guidance.