Accounting Cost of Goods Sold (Per-Unit) Calculator Examples
Worked weighted-average inventory examples showing COGS per unit, total COGS, and ending inventory value.
These examples show how changes in inventory quantities, purchase costs, and closing stock affect a periodic weighted-average COGS calculation. Each example uses cost data only, not sales revenue.
Small retailer with higher purchase costs
Beginning inventory: 100 units at $10.00; purchases: 400 units at $12.00; ending inventory: 150 units.
Input Summary
Beginning inventory
100 units at $10.00
Purchases
400 units at $12.00
Ending inventory
150 units
Calculation Breakdown
- 1Available cost(100 × $10.00) + (400 × $12.00)$5,800.00
- 2Available units100 + 400500 units
- 3Average cost$5,800.00 ÷ 500$11.60 per unit
- 4COGS(500 - 150) × $11.60$4,060.00
Result Summary
COGS
$4,060.00
Accounting Cost of Goods Sold (Per-Unit) Calculator
COGS is $11.60 per unit and $4,060.00 in total. Ending inventory is $1,740.00.
Stable-cost inventory example
Beginning inventory: 60 units at $25.00; purchases: 140 units at $25.00; ending inventory: 40 units.
Input Summary
Beginning inventory
60 units at $25.00
Purchases
140 units at $25.00
Ending inventory
40 units
Calculation Breakdown
- 1Available cost(60 × $25.00) + (140 × $25.00)$5,000.00
- 2Available units60 + 140200 units
- 3Average cost$5,000.00 ÷ 200$25.00 per unit
- 4COGS(200 - 40) × $25.00$4,000.00
Result Summary
COGS
$4,000.00
Accounting Cost of Goods Sold (Per-Unit) Calculator
COGS totals $4,000.00, while ending inventory is valued at $1,000.00.
Bulk purchase at a lower cost
Beginning inventory: 80 units at $18.00; purchases: 320 units at $15.00; ending inventory: 100 units.
Input Summary
Beginning inventory
80 units at $18.00
Purchases
320 units at $15.00
Ending inventory
100 units
Calculation Breakdown
- 1Available cost(80 × $18.00) + (320 × $15.00)$6,240.00
- 2Available units80 + 320400 units
- 3Average cost$6,240.00 ÷ 400$15.60 per unit
- 4Ending inventory value100 × $15.60$1,560.00
Result Summary
Ending inventory value
$1,560.00
Accounting Cost of Goods Sold (Per-Unit) Calculator
300 units sold produce total COGS of $4,680.00, with a weighted-average unit cost of $15.60.
How to Read Your Results
Cost of goods sold per unit is the weighted-average inventory cost, not the selling price or gross profit per unit.
Total COGS is the cost assigned to units sold during the period.
Units sold are inferred from available units less ending inventory units.
Ending inventory value is the cost assigned to units remaining using the same average cost.
Compare results only when inventory scope, currency, and accounting period are consistent.
Assumptions & Important Notes
- Examples use the periodic weighted-average method.
- No separate inventory adjustments, returns, or write-downs are included.
- Unit costs represent amounts consistently treated as inventory costs.
- Ending inventory counts are assumed accurate.
Related Examples
Frequently Asked Questions
Why do these examples use ending inventory instead of a sales-unit input?
Under this calculator, units sold are derived as units available for sale less ending inventory units.
What happens if ending inventory is zero?
All available units are treated as sold, so total COGS equals the full cost of goods available for sale.
Do more expensive purchases always increase COGS per unit?
Usually they increase the weighted average, but the size of the effect depends on the number of units purchased.
Can a business use a different inventory costing method?
Yes. FIFO, LIFO where permitted, and moving-average approaches can calculate different amounts.
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