Inventory Valuation Methods Compared: FIFO, Weighted Average, and Specific Identification
Your inventory is probably your largest asset. How you value it affects your balance sheet, your reported gross profit, your tax liability, and the accuracy of your pricing decisions.
Most businesses set their inventory valuation method when they first set up their accounting system — and then never revisit whether it's still the right choice. This guide gives you the comparison that should inform that decision.
For a full explanation of what FIFO and weighted average actually mean, see FIFO vs LIFO vs Weighted Average. Here, the focus is on comparing the outcomes.
The Scenario
You buy the same product three times at different prices (due to supplier price increases):
- January: 100 units at Rs. 100 each = Rs. 10,000
- March: 100 units at Rs. 120 each = Rs. 12,000
- May: 100 units at Rs. 140 each = Rs. 14,000
Total: 300 units at a total cost of Rs. 36,000.
In June, you sell 150 units.
Under each valuation method, here's what your COGS and remaining inventory look like:
FIFO (First In, First Out)
FIFO assumes the oldest units are sold first.
Units sold (150): 100 units from January (Rs. 100 each) + 50 units from March (Rs. 120 each)
COGS = Rs. 10,000 + Rs. 6,000 = Rs. 16,000
Remaining inventory: 50 units from March (Rs. 120 each) + 100 units from May (Rs. 140 each) = Rs. 6,000 + Rs. 14,000 = Rs. 20,000
Observation: In a rising price environment, FIFO produces the lowest COGS (oldest, cheapest stock sold first) and the highest inventory valuation (remaining stock is priced at the most recent, highest costs). This means higher reported profit — and higher tax.
Weighted Average Cost
Weighted average calculates a single blended cost per unit from all available inventory.
Average cost per unit = Rs. 36,000 ÷ 300 = Rs. 120
COGS = 150 × Rs. 120 = Rs. 18,000
Remaining inventory = 150 × Rs. 120 = Rs. 18,000
Observation: Weighted average produces a COGS and inventory value between the FIFO and LIFO extremes. Margin reporting is smoother because you're not hitting peaks and valleys based on which batch's costs happen to be flowing through.
Specific Identification
Specific identification tracks the actual cost of each individual unit. You need to know exactly which units were sold and what those specific units cost.
This method is only practical for:
- High-value, individually distinguishable items (vehicles, equipment, custom-manufactured products, jewelry)
- Products with serialized tracking where you can match a specific serial number to its purchase cost
For a business selling commodity products or high-volume consumer goods, specific identification is impractical — you can't track which individual unit of a product went to which customer.
When used: The COGS for the 150 units is the sum of the actual purchase prices for those specific 150 units. If you can demonstrate exactly which units were sold, this produces the most accurate cost assignment.
Side-by-Side Comparison
| | FIFO | Weighted Average | Specific ID | |--|------|-----------------|-------------| | COGS (rising prices) | Lowest | Middle | Actual | | Inventory value (rising prices) | Highest | Middle | Actual | | Reported profit (rising prices) | Highest | Middle | Actual | | Complexity | Low | Low | High | | Practical for high-volume | Yes | Yes | No | | Allowed under IFRS | Yes | Yes | Yes |
The Tax Timing Implication
In a rising price environment (which describes most businesses most of the time):
- FIFO → higher profit → higher current tax bill
- Weighted average → middle profit → middle tax bill
This is a cash flow consideration, not a financial reality difference. The goods cost what they cost. The method affects when you recognize that cost, not the total cost over time.
If cash flow is tight, a weighted average method smooths the profit impact of price volatility, which can make tax payments more predictable.
The Landed Cost Factor
Both FIFO and weighted average need to be calculated on landed cost, not purchase price.
If you're using FIFO and recording January's purchase at purchase price (ignoring freight and duties) while March's purchase reflects full landed cost, your FIFO layers are inconsistent. The resulting COGS calculation is neither accurate FIFO nor accurate weighted average — it's just wrong.
This is one of the most common inventory costing errors in businesses that import goods.
How to Choose
Use FIFO if:
- You physically rotate stock FIFO (food, pharma, anything with expiry)
- Your costs are stable or declining
- You want balance sheet inventory closest to current replacement cost
Use Weighted Average if:
- Your products are fungible (interchangeable units, not individually distinguishable)
- Prices fluctuate and you want smooth margin reporting
- You have high purchase frequency
Change your method rarely: Switching inventory valuation methods mid-year creates accounting complexity (restatement of prior period comparisons). If you want to change, do it at the start of a financial year with your accountant's guidance.
What Your Software Does Matters
The valuation method you choose is only as accurate as the system implementing it.
A system that tracks FIFO needs to maintain purchase cost layers — each batch purchase at its own cost — and ensure that units dispatched are always drawn from the oldest available layer. If the system uses purchase order date as a proxy for "oldest" without tracking actual receipt date and cost, the FIFO result is approximate, not precise.
Accounting and inventory software built for inventory businesses handles this automatically — maintaining cost layers or blended averages per product, updating in real time with each transaction, and producing the COGS and inventory values that flow correctly into your P&L and balance sheet.
Sevenledger supports FIFO and weighted average costing, with landed cost allocation built in — so your inventory valuation is accurate from the moment goods are received.