Payback period calculator
Calculate a simple payback period in months and years from the initial investment and monthly or yearly net cash inflow. View the whole months needed after rounding up, then copy the results or save them as text. Net cash inflow is assumed to remain constant and arrive evenly during each period; discounting, tax adjustments and changes in later cash inflows are excluded.
What you can do
View payback in months and years
View a simple payback period in months and years from initial investment and constant net cash inflow.
Check rounded-up months
Compare fractional months with the whole months needed after rounding up.
Copy or save the results
Copy the calculation results together or save them as a text file.
How to use
Enter the initial investment
Enter the amount invested initially. Zero or positive amounts are accepted.
Enter net cash inflow and its period
Enter monthly or yearly net cash inflow and select its period. Distinguish net cash inflow from gross sales.
View the payback period
Check months, rounded-up whole months and years. Copy the results or save them as text.
When this is useful
Estimate time to recover an investment
Find an approximate payback period when monthly or yearly net cash inflow remains constant.
Compare net cash inflow assumptions
Change the investment or net cash inflow per period to compare payback periods.
Calculation assumptions
Conversion to months and years
For monthly inflow, initial investment ÷ net cash inflow gives months. For yearly inflow, multiply that value by 12 to convert it to months. Years are months ÷ 12, and required months are rounded up to a whole number.
Constant net cash inflow
Net cash inflow is assumed to remain constant and arrive evenly during each period. Discounting, tax adjustments, changes in later cash inflows and additional investments are excluded.
Frequently asked questions
What happens when net cash inflow is zero?
With positive initial investment, the result states that there is no payback. With zero initial investment, the payback period is zero.
Does the calculation consider actual yearly payment dates?
No. Inflow is assumed to arrive evenly during each period. Actual payment dates or payments made only at year-end are not modeled.
Can I enter negative amounts?
Input amounts must be nonnegative. Payback with negative net cash inflow or changing cash flows is not modeled.
Inputs and results
- Input
- Initial investment, net cash inflow per period and monthly or yearly selection. Amounts range from 0 to 1,000,000,000,000 with at most six decimal places.
- Output
- Payback in months, rounded-up whole months and payback in years. Copy the results or save payback-period-calculator.txt.
- Changes
- Editing an input or changing the period clears the previous result. Calculate again using the new conditions.