Steps To Calculate ARR:-
1-- Calculate
Avg. earnings after taxes(during project period) = Total expected earnings after taxes but before interest on long term debt / Total project period.
2-- Calculate Avg. investment in project.
(a) Avg Investment(each year) = (Opening Investment* + closing investment*) / 2
* includes working capital if any.
(b) Avg. Investment(during project period-n) = ( Step 2(a) for 1st yr +..... step 2(a) for n yrs) / n
OR
Short cut formula for calculating avg. investment when SLM of Depreciation is used----
Here, Avg Inv.= 1/2(original cost - salvage value) +salvage value + working capital
3--- At last ,
ARR = STEP 1 result / Avg investment during project period as per step 2(b)