Since the product has 1,000 in-production units, overhead cost per unit is calculated as $5,100/1,000 units = $5.10 per unit. This is less compared to the $7 per unit overhead cost calculated using the traditional overhead cost allocation, but it reflects more of the actual overhead cost behaviors.ssume that for the entire production, the business conducted 10 tests, 15 setups and 20 cleaning jobs. Thus, the unit cost for each overhead activity is as follows: $5,000/10 tests = $500 per test, $3,000/15 setups = $200 per setup and $2,000/20 cleaning jobs = $100 per cleaning job.