Inventory valuation calculator

How to use the calculator

1. Name the item and its unit (carton, bag, litre) and choose the currency.
2. Enter the opening stock: the quantity on hand at the start of the period and what each unit cost.
3. Add each purchase with its date, quantity and cost per unit, excluding any VAT you can reclaim.
4. Add each sale with its date and quantity. You do not need the selling price; this is about cost.
5. Read cost of goods sold and closing stock under each method, then download the workings.

Lines are taken in date order; lines on the same date are taken in the order you entered them. If a sale is larger than the stock on hand at that point, the calculator tells you which line, because the figures cannot be right.

FIFO and weighted average, worked through

• FIFO: the oldest units are treated as sold first, so closing stock is valued at the most recent prices.
• Weighted average (periodic): average cost = (opening stock value + purchases) ÷ (opening units + units bought); cost of goods sold = units sold × that average.
• Moving average (perpetual): the average is recalculated after each purchase, and each sale is costed at the average at that moment.
• In every method, opening stock + purchases = cost of goods sold + closing stock.

Load the example: 100 cartons at ₦10,000 on hand, 200 bought at ₦12,000, 150 sold, 100 bought at ₦15,000, then 180 sold. Under FIFO, cost of goods sold is ₦3,850,000 and the 70 cartons left are worth ₦1,050,000. The periodic average is ₦4,900,000 ÷ 400 = ₦12,250 a carton, giving cost of goods sold of ₦4,042,500 and closing stock of ₦857,500. The moving average gives ₦4,004,000 and ₦896,000. When prices are rising, FIFO shows the lowest cost of sales and so the highest profit.

The facts: what the standard allows

• Under IAS 2, inventories are measured at the lower of cost and net realisable value. If stock can only be sold for less than it cost, write it down.
• IAS 2 assigns the cost of interchangeable items using the first-in, first-out or the weighted average cost formula. Items that are not ordinarily interchangeable, such as made-to-order goods, use specific identification of their individual costs.

This calculator works out cost only. It does not test net realisable value: if any stock is damaged, expired or selling below cost, reduce its value yourself.

Sources, checked 2 November 2026: IFRS Foundation, IAS 2 Inventories.