Compute periodic weighted-average costs
See this course’s project requirements
A fictional inventory-cost ledger with FIFO and weighted-average comparison, returns, write-down case and reconciled gross profit.
Keep your working files in your own notebook or software. Save a private description, checklist, and work link in My Proof.
What to include
- A unit roll-forward and available-cost identity.
- A FIFO layer worksheet and gross-profit bridge.
- A periodic weighted-average comparison with FIFO and rounding notes.
- A returned-purchase and landed-cost valuation ledger.
- A supported damaged-inventory value adjustment and quantity/value bridge.
- A final inventory-cost and gross-profit reconciliation packet.
Review and revise
Use these criteria to check your work and choose what to improve.
- Units: acquisitions, returns, sales and count reconcile.
- Valuation: FIFO and average use correct layers/pool.
- Loss: supported affected-unit adjustment is explicit.
- Profit: cost destinations and classification reconcile.
Want more background?
The idea in everyday life
Original fictional practice. All money is USD. No account, payment, personal record or outside participation is required. Fictional periodic inventory of identical notebooks: beginning 10 units at 4=40; buy 20 at 5=100; sell 18 at 10=180 revenue. Initial count 12 remain. Later variation: return 4 purchase units before any sales and pay 16 inbound freight allocated only to the 16 retained purchased units. Adjusted goods available 26 units/cost 136; sell 18, ending count 8. For the loss case use FIFO, of the eight unsold units two are damaged, cost 6 each and supported net realizable value 1 each. Exercise policy records the 10 loss within COGS; no tax policy or real standard election is implied. Original changed-case support labels: RET-04 documents the four-unit supplier return before sales; FRT-16 allocates freight 16 to the retained purchase lot; LOSS-02 documents two ending units at cost 6 each and recoverable value 1 each. These are supplied fictional source labels for your audit index.
A weighted average weights acquisition cost by units, not by the number of purchase rows.
Compute periodic weighted-average costs — complete worked case
A weighted average weights acquisition cost by units, not by the number of purchase rows.
Fictional periodic inventory of identical notebooks: beginning 10 units at 4=40; buy 20 at 5=100; sell 18 at 10=180 revenue. Initial count 12 remain. Later variation: return 4 purchase units before any sales and pay 16 inbound freight allocated only to the 16 retained purchased units. Adjusted goods available 26 units/cost 136; sell 18, ending count 8. For the loss case use FIFO, of the eight unsold units two are damaged, cost 6 each and supported net realizable value 1 each. Exercise policy records the 10 loss within COGS; no tax policy or real standard election is implied. Original changed-case support labels: RET-04 documents the four-unit supplier return before sales; FRT-16 allocates freight 16 to the retained purchase lot; LOSS-02 documents two ending units at cost 6 each and recoverable value 1 each. These are supplied fictional source labels for your audit index.
Initial original ledger
Paste at A1.
| ARecord | BUnits | CUnit cost | DCost or revenue |
|---|---|---|---|
| Beginning | 10 | 4 | 40 |
| Purchase | 20 | 5 | 100 |
| Sale | 18 | Selling 10 | 180 |
| Initial closing count | 12 | Unassigned | To calculate |
Copy as plain text
1. 3.1 Compute
Add available units and total cost before dividing.
You should see: 30 units and 140 cost.
2. 3.2 Compute
Divide 140/30 and retain unrounded average for products.
You should see: 4.6666667 per unit.
3. 3.3 Compute
Multiply by sold 18 and remaining 12, round final values, then reconcile.
You should see: COGS 84 and ending 56.
4. 3.4 Compute
Change only the purchase price to 6; recompute available 160/30 and 18-unit COGS 96.
You should see: Ending 64;160=96+64.
What to finish
A periodic weighted-average comparison with FIFO and rounding notes.
Watch for this
Averaging the two listed unit prices without weighting their quantities.
How can I tell I understand it?
Verify that your completed periodic weighted-average comparison with FIFO and rounding notes meets the three lesson-specific checks and retains the supporting original records.
Quick knowledge check
Answer all 3 questions. Get at least 2 right and the lesson completes automatically.
You’ll get an explanation for each answer. Signed in? Your results save to your account.
Pass the check. We’ll save the progress.
Answer all 3 questions above and get at least 2 right. You can review the explanations and try again.
Go to the knowledge checkTools, templates, and lesson sources
Tools and templates
Tools open in a new tab so you can keep your place here.
Sources and further reading
Explore the references behind this lesson.
Source & access notes · checked 2026-10-01
Read FIFO, weighted average, historical cost and lower-of-cost discussion; original quantities/costs/NRV policy supplied here.
Access: Public primary page body opened and relevant sections read through the web reader on 2026-10-01; no account required for reading.
Reuse: Original Life Starter cases, datasets and questions; no source exercise or worked dataset reproduced. Links support further reading.
Source & access notes · checked 2026-10-01
Read periodic whole-period average and cost allocation mechanics; all original practice uses this explicitly named periodic method.
Access: Public primary page body opened and relevant sections read through the web reader on 2026-10-01; no account required for reading.
Reuse: Original Life Starter cases, datasets and questions; no source exercise or worked dataset reproduced. Links support further reading.
Report a problem with this lesson
Tell us what went wrong. Please leave out personal information and private project contents.