Payback: How to Calculate the Payback Period of an Investment
Before any investment decision — whether buying a machine, opening a business, renovating or purchasing equipment — one of the first questions is: "How long will it take for me to recover what I invested?" The answer is payback, and understanding it correctly can be the difference between a smart investment and a financial mistake.
In this guide, you will learn the two ways to calculate payback (simple and discounted), when to use each one, the limitations of the metric and how to interpret it in practice. Use our Payback Calculator to simulate any project.
What is Payback?
Payback (or Payback Period) is the time necessary for the positive cash flows generated by an investment to fully recover the capital initially invested. In other words: how long to "pay for yourself".
It is one of the simplest and most intuitive metrics for analyzing financial viability — and one of the most used by entrepreneurs and managers on a daily basis.
Simple Payback vs Discounted Payback
There are two variants:
| Simple Payback | Discounted Payback | |
|---|---|---|
| Do you consider the time value of money? | ❌ No | ✅ Yes |
| Do you use discount rate? | ❌ No | ✅ Yes |
| Ease of calculation | Very simple | Moderate |
| Accuracy | Minor | Biggest |
| Use | Rapid initial screening | Rigorous financial analysis |
How to Calculate Simple Payback
Scenario 1: Uniform Cash Flows (Annuities)
When returns are equal in all periods:
Payback = Initial Investment / Annual Cash Flow
Example: A machine with $ 120.000 que gera $ 30,000 profit per year:
Payback = R$ 120.000 / R$ 30.000 = 4 anos
Scenario 2: Variable Cash Flows
When returns differ each period, accumulate the flows until the investment is zero:
| Year | Cash Flow | Accumulated Flow |
|---|---|---|
| 0 | − $ 200.000 | − $ 200,000 |
| 1 | + $ 50.000 | − $ 150,000 |
| 2 | + $ 70.000 | − $ 80,000 |
| 3 | + $ 80.000 | $ 0 |
| 4 | + $ 90.000 | + $ 90,000 |
Simple Payback = 3 exact years (accumulated flow resets to zero at the end of year 3)
If zero does not fall exactly at the end of the year:
Payback = Year Previous to Zero + (Remaining Negative Balance / Next Year's Flow)
Example with partial payback:
| Year | Cash Flow | Accumulated Flow |
|---|---|---|
| 0 | − $ 200.000 | − $ 200,000 |
| 1 | + $ 50.000 | − $ 150,000 |
| 2 | + $ 70.000 | − $ 80,000 |
| 3 | + $ 90.000 | + $ 10,000 |
Payback = 2 + (R$ 80.000 / R$ 90.000) = 2 + 0,889 = 2,89 anos ≈ 2 anos e ~10,7 meses
How to Calculate Discounted Payback
The discounted payback considers that $ 1.000 hoje vale mais que $ 1,000 in the future (due to inflation and the opportunity cost of money). To do this, each future cash flow is discounted at a minimum attractive rate (MAR):
FCL Discounted_t = FCL_t / (1 + TMA)^t
Example: Same project with ARR of 12% per year
| Year | Original Stream | Discount Factor (12%) | Discounted Flow | Accumulated Discounted |
|---|---|---|---|---|
| 0 | − $ 200.000 | 1,000 | − $ 200,000 | − $ 200.000 |
| 1 | + $ 50,000 | 0.893 | + $ 44.643 | − $ 155,357 |
| 2 | + $ 70.000 | 0,797 | + $ 55,801 | − $ 99.556 |
| 3 | + $ 80,000 | 0.712 | + $ 56.943 | − $ 42,613 |
| 4 | + $ 90.000 | 0,636 | + $ 57.211 | + $ 14,598 |
Payback Descontado = 3 + (R$ 42.613 / R$ 57.211) = 3 + 0,745 = 3,74 anos ≈ 3 anos e ~9 meses
Compare: the simple payback indicated ~2.89 years; discounted with a 12% MARR indicates ~3.74 years. This difference is relevant in investment decisions.
When is Payback the Right Metric?
| Situation | Is Payback Recommended? |
|---|---|
| Initial screening of multiple projects | ✅ Excellent for quickly comparing |
| Short-term projects (< 3 years) | ✅ Simple and effective |
| High uncertainty environments (high risk) | ✅ Shorter term = lower risk |
| Company liquidity analysis | ✅ Focus on cash recovery |
| Long-term projects (> 10 years) | ⚠️ Use DCF or NPV as a complement |
| Comparison of projects with different useful lives | ❌ Inappropriate — use NPV/IRR |
| Full Company Valuation | ❌ Insufficient — use DCF or multiples |
Payback x NPV x IRR: Which One to Use?
The three main investment analysis metrics complement each other:
| Metric | What it measures | Advantage | Limitation |
|---|---|---|---|
| Payback | Recovery time | Simple, focus on liquidity risk | Ignore returns after payback |
| NPV (Net Present Value) | Value creation in $ | Considers time value of money | More complex, depends on the TMA |
| IRR (Internal Rate of Return) | Profitability % of the project | Easy Comparison with Cost of Capital | Can have multiple results in alternating FCLs |
Recommendation: Use payback as initial screening. For projects that pass the payback criteria, drill down with NPV and IRR.
Reference Table: Payback by Sector/Type of Investment
| Type of Investment | Typical Acceptable Payback |
|---|---|
| Industrial equipment | 2 to 5 years |
| Photovoltaic solar energy (residential) | 4 to 7 years |
| Rental property renovation | 8 to 15 years |
| Agricultural machinery | 3 to 6 years |
| Enterprise Software (SaaS) | 6 to 18 months |
| Technology Startup | 3 to 7 years |
| Food franchise | 18 to 36 months |
| Solar power plant (large scale) | 5 to 8 years |
Payback Limitations
Ignores cash flows after the payback period: Two projects with the same 3-year payback can have very different total returns in years 4, 5, 6...
Does not consider the time value of money (simple version): $ 100.000 no ano 1 valem mais que $ 100,000 in year 3. The simple payback ignores this.
Does not indicate profitability: A project can have a payback of 2 years but generate only 5% total return — lower than the CDI.
Short-term bias: Managers evaluated by payback tend to reject high-value, long-term projects, favoring those with quick returns but lower total value.
Frequently Asked Questions (FAQ)
1. What is the difference between simple payback and discounted payback?
The simple payback adds the nominal cash flows (without adjustment for time) until the investment is recovered. Discounted payback discounts each future flow by a minimum attractiveness rate (MAR), recognizing that future money is worth less than money today. Discounted payback is more accurate but requires defining the appropriate AMR.
2. How to define whether a payback is good or bad?
It depends on the sector and the TMA. Generally, the payback must be less than the useful life of the asset/project. For retail/service businesses, a payback of 1-3 years is considered good. For infrastructure and real estate, 5-15 years may be acceptable. Always compare with alternative projects and the opportunity cost of capital.
3. How to calculate the payback for a restaurant/retail business?
Total investment (renovation + equipment + working capital) divided by expected net monthly profit. Example: investment of $ 150.000 com lucro projetado de $ 8,000/month = payback of 18.75 months (≈ 1.5 years). Attention: use actual net profit, not revenue.
4. Does the payback consider depreciation?
Payback analyzes cash flow, not accounting profit. Depreciation is a non-cash accounting cost — it does not reduce cash, only income. Therefore, when calculating payback, you use free cash flow (profit + depreciation = cash generated). The cash generated is always greater than the accounting net profit.
5. Is a project with a 2-year payback always better than a 4-year one?
Not necessarily. A 2-year payback project may only generate $ 10.000 de valor adicional após o payback, enquanto um de 4 anos pode gerar $ 500,000. Payback is a risk screening metric, not total profitability. Complete the analysis with NPV to compare actual value creation.
6. What is the difference between payback and ROI?
Payback measures time to recover the investment. ROI (Return on Investment) measures the percentage of return on investment. They are complementary: the payback tells you when you recover, the ROI tells you how much you earned over the entire period. Use our ROI Calculator to calculate your project's percentage return.
Simulate Now
Use our Payback Calculator to:
- Calculate simple and discounted payback
- Insert variable cash flows per period
- Compare two projects by payback
Related calculators:
- ROI Calculator — calculate the percentage return on investment
- Valuation Calculator — determine the value of the company or project
- Break-even Calculator — calculate the minimum sales volume
- Profit Margin Calculator — calculate the profitability of the business