Add purchase batches, enter units sold — see COGS and ending inventory under First In, First Out
Quick presets:
FIFO Cost of Goods Sold
| Batch | Purchased | Unit Cost | Units Used | COGS from Batch | Remaining |
|---|---|---|---|---|---|
| Enter batches and units sold to see the breakdown | |||||
| Total | 0 | 0 | $0.00 | 0 | |
FIFO (First In, First Out) is an inventory valuation method that assumes the oldest stock is sold first. When you calculate cost of goods sold, FIFO assigns the cost of your earliest purchases to the units sold and values remaining inventory at the most recent purchase prices. This matches how most ecommerce businesses actually move stock — older inventory ships before newer arrivals to prevent spoilage, obsolescence, or dead stock buildup.
Imagine you run a Shopee store selling phone cases. You purchased 100 units at $5 in January, then 150 units at $6 in February. You sold 120 units during the quarter. Under FIFO, all 100 units from the $5 batch are consumed first, then 20 units from the $6 batch. Your COGS is (100 × $5) + (20 × $6) = $620. The remaining 130 units are valued at $6 each = $780 ending inventory. This calculator automates exactly this process for any number of purchase batches.
Under FIFO, COGS reflects older (usually lower) costs, resulting in higher reported profit and higher ending inventory values during periods of rising prices. Under LIFO (Last In, First Out), COGS reflects newer (usually higher) costs, lowering reported profit but reducing tax liability. Most ecommerce sellers and all businesses reporting under IFRS (used in Singapore, the EU, and most of Asia) must use FIFO. LIFO is only permitted under US GAAP. If you sell on Shopee, Lazada, or other Southeast Asian marketplaces, FIFO is your required method.
When you sell across multiple platforms, each channel draws from shared inventory. FIFO ensures consistent cost allocation regardless of which marketplace the order came from. Without a systematic valuation method, sellers often miscalculate margins by assigning arbitrary costs to sales. This becomes critical during supplier price changes — if your widget cost rises from $8 to $10 per unit, FIFO correctly assigns the $8 cost to earlier sales and $10 to later ones, giving you accurate per-channel profitability. Tools like OneCart help multi-channel sellers track inventory across platforms so every unit's cost is accounted for.
Calculate FIFO valuation at least monthly for tax and accounting purposes, and weekly if you manage fast-moving inventory. Key triggers for recalculation include: receiving new stock at different prices, completing a stock count, preparing financial statements, or analysing product profitability. Pair this calculator with our safety stock calculator for reorder planning and the reorder point calculator to time your next purchase.