Calculated from the sample figures using the displayed formula.
What is the payback period formula?
Initial investment ÷ Equal annual cash inflowSimple payback period estimates how long equal cash inflows take to recover an initial investment.
What do the inputs mean?
- Initial investment
- The value entered for initial investment. Keep its period and units consistent with the other inputs.
- Equal annual cash inflow
- The value entered for equal annual cash inflow. Keep its period and units consistent with the other inputs.
How to calculate it step by step
- Define the decision.
Write down what the result will help you compare or decide. - Collect matching inputs.
Use figures from the same period and apply the definitions shown on this page. - Apply the formula.
Initial investment ÷ Equal annual cash inflow. - Check the units.
Confirm whether the result is a currency amount, percentage, number of periods or ratio. - Test a second case.
Change one assumption at a time to see what drives the result.
Worked example
Using the sample figures in the calculator, the result is 3.75 years. Change one figure at a time and recalculate to see which assumption has the greatest effect. A spreadsheet should return the same result when it uses the same formula, units and timing.
When should you use payback period formula?
Use it as a liquidity screen alongside, not instead of, value-based methods.
Limitations and common mistakes
Simple payback ignores the time value of money and cash flows after recovery.
Do not mix annual figures with monthly figures, ending balances with averages, or percentages with whole numbers. Record the definition used so another person can reproduce the result.
Frequently asked questions
What is payback period formula?
Simple payback period estimates how long equal cash inflows take to recover an initial investment.
How should I use payback period formula?
Use the formula only after matching every input to the same period, unit and definition. Then compare the result with a worked example and the decision you are trying to make.
What is the most common mistake with payback period formula?
Simple payback ignores the time value of money and cash flows after recovery.
Can I calculate payback period formula in a spreadsheet?
Yes. Reproduce the displayed equation with separate cells for each input, keep percentages as decimals, and test the spreadsheet against the worked example before replacing the sample figures.
Sources and methodology
This page uses the Financial definitions for the underlying financial or reporting context. Spreadsheet-related behavior is checked against Microsoft’s financial-function documentation. Examples are illustrative and use the formula displayed on the page.