π FIFO Inventory Calculator
Which batches did your sales eat first?
FIFO cost of goods sold
Estimates for planning only, not financial advice.
First in, first out assumes the oldest stock sells first, like milk on a grocery shelf. When prices rise, FIFO assigns the cheaper old costs to goods sold and leaves the pricier recent costs in ending inventory, which raises reported profit and the balance-sheet stock value alike. This calculator walks the layers exactly as accountants do.
How to Use This Calculator
The Formula
Ending inventory is whatever the sales did not touch, valued at the most recent costs. For the period-end rollup, see our ending inventory calculator.
Worked Example
You buy 100 units at $10, then 100 units at $12, then sell 150 units. FIFO consumes all 100 of batch 1 ($1,000) plus 50 of batch 2 ($600): COGS = $1,600. Ending inventory is the remaining 50 units of batch 2 at $12 = $600. Check: $1,600 + $600 = $2,200, exactly the $1,000 + $1,200 purchased. In rising prices this $1,600 COGS is lower than LIFO would give, so FIFO reports higher profit.
Tips for FIFO Users
FIFO matches physical flow for perishables, which is why grocers and pharma default to it; the accounting mirrors the warehouse. In inflationary times expect higher taxable income than under LIFO, a real cash cost of the method choice. Track batches in your inventory system with dates, because FIFO audits reconstruct exactly this layer walk. And stay consistent: switching methods to manage earnings invites auditor and regulator attention.
Common Mistakes
Selling more units than purchased produces negative layers, the classic spreadsheet error this calculator blocks. Mixing units and dollars, entering batch totals as unit costs, silently corrupts everything. Forgetting that purchase returns reduce the batch quantities overstates both COGS and ending stock. And applying FIFO to the physical flow while using average cost in the books creates two truths that reconcile painfully at year end.
FIFO vs LIFO vs Average
In rising prices: FIFO gives the lowest COGS and highest profit and inventory; LIFO the reverse; weighted average sits between. LIFO is banned under IFRS, so multinationals standardize on FIFO or average. The choice affects taxes, bonuses tied to profit, and loan covenants, which is why it is a board-level decision disguised as an accounting detail. Pick for economics, disclose clearly, and never switch casually.
FIFO liquidation is the hidden tax bomb: when sales exceed purchases, ancient low-cost layers flow into COGS, creating surprisingly low taxable income in the good sense, or surprisingly high profit that spikes taxes. Companies in declining industries face this as inventory drains, reporting profits while the business shrinks. Analysts strip out the liquidation effect to see the underlying trend.
Disclosure rules help: companies must reveal when a LIFO liquidation or material FIFO layer change affects income, usually in the inventory footnote. Make the footnote a habit, not an afterthought; the most important sentence in an inventory-heavy 10-K is often buried there. What management highlights is marketing; what the footnotes whisper is accounting.
FIFO in Inflationary Periods
Persistent inflation makes FIFO report phantom profits: COGS reflects old cheap costs while replacement stock costs far more, so the "profit" cannot actually fund restocking. A grocer showing 5 percent margins on FIFO during 8 percent food inflation may be liquidating its inventory's real value while the income statement applauds.
US companies may elect LIFO to match current costs against revenue, cutting taxable income during inflation, but IFRS bans it and the LIFO conformity rule forces its use in financial statements too, depressing reported earnings. The choice is genuinely strategic: pay less tax now (LIFO) or report stronger earnings (FIFO).
Investors should adjust: compare FIFO and LIFO reporters on a cash basis, and watch inventory profits, the gain from holding appreciating stock, which flatter FIFO earnings in inflation. The footnotes disclose the LIFO reserve, letting you convert. Inflation rewards those who read past the headline method.
The Average Cost Alternative
Weighted average costing smooths every purchase into one blended unit cost, recalculated after each batch. With 100 units at $10 and 100 at $12, the average is $11; selling 150 gives COGS of $1,650 and ending inventory of $550. It sits between FIFO's $1,600/$600 and LIFO's $1,700/$500, damping volatility.
The method suits commodities and bulk goods where batches are indistinguishable: fuel, grain, chemicals. Its simplicity is the selling point: no layer tracking, no batch archaeology at audit time. The cost is precision: average costing lags both FIFO and LIFO in reflecting current economics.
Switching methods is a formal accounting change requiring disclosure and often restatement, so choose with a decade's horizon. For stable prices all methods converge and simplicity wins; for volatile prices the choice shapes taxes and bonuses. Match the method to the business's price environment, not to this year's earnings target.
Estimates for planning only, not financial advice.
Frequently Asked Questions
What is the FIFO method?
First in, first out: the oldest inventory is assumed sold first. COGS reflects older costs; ending inventory reflects recent costs.
How do you calculate FIFO COGS?
Consume purchase batches oldest-first: multiply units taken from each batch by that batch unit cost, and sum.
Does FIFO give higher profit?
In rising prices, yes: cheaper old costs go to COGS, leaving pricier stock on the balance sheet. In falling prices the reverse holds.
Is FIFO allowed under IFRS?
Yes. FIFO and weighted average are permitted; LIFO is prohibited under IFRS (though allowed under US GAAP).
What is a FIFO layer?
Each purchase batch is a layer with its own quantity and unit cost. Sales peel layers off oldest-first.
How does FIFO affect taxes?
In inflation, FIFO reports higher profit than LIFO and therefore higher taxable income. The method choice has cash consequences.
Can you switch from FIFO to LIFO?
Only with justification and disclosure; it is a change in accounting principle requiring restatement and regulatory notice.
Does FIFO match physical flow?
Often yes for perishables, which is its intuitive appeal. But it is a cost-flow assumption, and physical flow may differ.
What if I sell more than I bought?
That signals missing purchase records or data entry error. Investigate before reporting; negative inventory is impossible.
FIFO vs weighted average: which is better?
FIFO tracks recent costs in inventory more precisely; average is simpler with many small purchases. Either beats inconsistency.