## Accounting Rate of Return (ARR)
The Accounting Rate of Return (also called Average Rate of Return) is a non-discounting capital budgeting technique. It measures the average annual net income (accounting profit) of a project as a percentage of the investment.
> ARR uses profit after depreciation (accounting profit) — not cash flows. This is what distinguishes it from payback and the discounting methods.
### Core formula
$$\text{ARR} = \frac{\text{Average annual net income}}{\text{Investment}} \times 100$$
- Numerator — the average annual net income (profit after depreciation, and after tax where applicable) generated over the project's useful life.
- Denominator — can be measured two ways:
- Initial investment (including installation cost), or
- Average investment over the useful life.
Average investment = the average amount of funds remaining blocked during the project's life.
### Three versions of ARR
Because both numerator and denominator can be defined differently, three versions are commonly used:
| Version | Numerator | Denominator |
|---|---|---|
| 1. Annual basis | Profit after depreciation (each year) | Investment at beginning of that year |
| 2. Total investment basis | Average annual profit | Initial investment |
| 3. Average investment basis | Average annual profit | Average investment |
Average investment can be computed as:
$$\text{Average Investment} = \frac{\text{Initial Investment} + \text{Salvage Value}}{2}$$
or equivalently:
$$\text{Average Investment} = \tfrac{1}{2}(\text{Initial Investment} - \text{Salvage Value}) + \text{Salvage Value}$$
### Adjusting for additional working capital
A project may need additional working capital during its life (beyond initial working capital). The average investment formula is then modified to:
$$\tfrac{1}{2}(\text{Initial Investment} - \text{Salvage Value}) + \text{Salvage Value} + \text{Additional Working Capital}$$
Adding working capital increases the denominator and therefore lowers the ARR.
### Decision rule
Accept a project if its ARR exceeds the firm's required/cut-off rate; for ranking, prefer the project with the higher ARR.