# Payback Period Calculator

URL: https://speedycalculator.com/calculators/finance/payback-period/
Last updated: 2026-10-25

> The payback period calculator works out how long it takes for an investment to earn back its cost, for even or uneven cash flows, and the discounted payback period that accounts for the time value of money.

## Inputs

- Initial investment
- Cash flows
- Annual cash flow
- Cash flow in each year
- Discount rate (%)

## Results

- Payback period
- Discounted payback period
- Net present value of the cash flows

## Formula

```
Even cash flows: payback = initial investment ÷ annual cash flow
Discounted payback: years until Σ CFₜ ÷ (1 + r)^t ≥ initial investment
With even flows: n = −ln(1 − I × r ÷ CF) ÷ ln(1 + r)
```

## Explanation

Payback is a quick, intuitive screen for investments: the shorter, the less risky. Its weakness is that it ignores cash flows after the payback point; the discounted version also ignores them but at least values money correctly over time.

### How to use the Payback Period Calculator

- **Initial investment**
- **Cash flows**
- **Annual cash flow**
- **Cash flow in each year**
- **Discount rate**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Enter the initial investment, the yearly cash flow (or a list of yearly cash flows) and the discount rate.

### Tips

- Use figures for the same period (a month, a quarter or a year) for every input so ratios compare like with like.
- Track the metric over time – the trend usually tells you more than a single value.
- Compare your result with industry benchmarks, which vary a lot between sectors.
- Treat the result as a starting point for a decision, then check the assumptions behind each input.

### Common mistakes to avoid

- Mixing monthly and yearly numbers in the same calculation.
- Using revenue where the formula needs profit (or the other way round).
- Forgetting hidden costs such as taxes, fees, overheads or your own time.

### Inputs explained

FieldWhat to enterInitial investmentAmount in your currencyCash flowsChoose one: Same every year, Different each yearAnnual cash flowAmount in your currencyCash flow in each yearA list of numbers separated by commas, spaces or new linesDiscount rateIn %

### Example values

How the main result changes when **Initial investment** changes and everything else stays at the example values above:

Initial investmentPayback period (years)25,0001.7937,5002.6850,0003.5762,5004.4675,0005.36100,0007.14

## Worked example

Inputs — Initial investment: $50,000; Cash flows: Same every year; Annual cash flow: $14,000; Cash flow in each year: 10000, 12000, 15000, 18000, 20000; Discount rate: 8 %.

Results — **Payback period = 3.57 years**; Discounted payback period = 4.37 years; Net present value of the cash flows = $5,897.94.

## FAQ

**What is a good payback period?**
Shorter is safer; many firms require 2–5 years depending on the project.

**Why use the discounted payback period?**
It accounts for the fact that future cash is worth less than cash today.

**What is the main weakness of payback?**
It ignores cash flows after the investment is recovered.

**What formula does the Payback Period Calculator use?**
Even cash flows: payback = initial investment ÷ annual cash flow.


## Sources

- [Corporate Finance Institute – financial ratios](https://corporatefinanceinstitute.com/)