Q.The average age of inventory is viewed as the average length of time inventory is held by the firm. Explain with reasons.

Let’s start with something you already know. Suppose you run a small shop that sells cold drinks. You buy a crate of 24 bottles for ₹480 and sell them over a week. At the end of the week, you have 6 bottles left. How many times did you “turn over” your entire stock? You sold 18 bottles — that’s three-quarters of your stock. If you kept selling at that rate, you would have sold your entire stock in about 9 days. That idea — how quickly you sell and replace your inventory — is the Inventory Turnover Period.

Precise meaning

In accountancy, the Inventory Turnover Period (also called Stock Turnover Period) tells us the average number of days it takes for a business to sell its entire stock of goods. It is the flip side of Inventory Turnover Ratio (which is a number of times). The period is simply:

Inventory Turnover Period (in days) = $\frac{365}{\text{Inventory Turnover Ratio}}$

Where the Inventory Turnover Ratio itself is:

Inventory Turnover Ratio = $\frac{\text{Cost of Revenue from Operations}}{\text{Average Inventory}}$

• Cost of Revenue from Operations = Opening Inventory + Purchases + Direct Expenses – Closing Inventory (this is the cost of goods sold, as per NCERT).
• Average Inventory = $\frac{\text{Opening Inventory} + \text{Closing Inventory}}{2}$

So if a firm’s Inventory Turnover Ratio is 5, the Inventory Turnover Period is $365/5 = 73$ days. That means, on average, goods stay in stock for 73 days before being sold.

Why it matters

A short period (say 30 days) means goods sell fast — cash is recovered quickly, storage costs are low, and the risk of obsolescence is small. A long period (say 200 days) suggests slow-moving stock, which ties up capital, increases storage and insurance costs, and may lead to losses if goods become outdated or perishable.

But there is no single “good” number. A jewellery shop will have a much longer period than a vegetable vendor. The real test is comparing the period with the industry average or the firm’s own past data.

Accounting treatment

Here is the key point for your exam: Inventory Turnover Period is a ratio — it is not a journal entry. You do not debit or credit any account for it. It is a tool for analysis, not a transaction.

The accounting treatment that relates to inventory is the valuation of closing stock at the end of the year. That closing stock figure is used in the ratio. The journal entry for recording closing stock is:

But the Inventory Turnover Period itself is calculated after the Trading Account is prepared, using the figures from it.

Format / Proforma

The NCERT textbook does not give a separate “proforma” for the Inventory Turnover Period. It is simply a ratio shown in the Notes to Accounts or in the Analysis of Financial Statements section. However, the Trading Account provides the raw data. Here is the standard format of a Trading Account (as per NCERT Class 12): …