Cost Ratio

The cost ratio is a figure used in the retail method of estimating inventory, calculated by dividing the cost of goods available for sale by the retail, or selling-price, value of those same goods. It expresses, as a single percentage, the typical relationship between what a retailer paid for its merchandise and what it intends to sell that merchandise for, and that percentage is then applied to estimate the cost of ending inventory without needing a full physical count valued item by item at cost.

A retailer tracks both the cost and the retail value of its beginning inventory and its purchases throughout the period, then divides total cost by total retail value to arrive at the cost ratio. At the end of the period, the retailer determines ending inventory at retail value, often from a physical count priced at current selling prices, which is generally far faster than pricing a count item by item at cost, and then multiplies that retail-value figure by the cost ratio to estimate the cost of ending inventory.

If a retailer's goods available for sale cost $240,000 and have a retail value of $400,000, the cost ratio is 60%. If a physical count at the end of the period shows $100,000 of inventory remaining at retail value, the estimated cost of that ending inventory is $60,000, found by multiplying $100,000 by the 60% cost ratio. Cost of goods sold for the period can then be derived by subtracting that $60,000 from the $240,000 cost of goods available for sale.

Many retailers carry thousands of individual items at varying cost percentages, making a precise, item-by-item cost valuation of inventory slow and labor-intensive, particularly for interim financial statements that need to be produced quickly throughout the year. The retail method, built around the cost ratio, lets a retailer produce a reasonably reliable estimate of inventory cost using retail-priced counts, which store staff can usually complete much faster than a cost-priced count, since retail price tags are generally already visible on the merchandise itself.

The cost ratio assumes a reasonably consistent relationship between cost and retail price across the mix of merchandise being estimated, an assumption that breaks down if a retailer sells a wide variety of products with very different markup percentages, or if markdowns and promotional pricing have significantly altered the retail value of inventory without a corresponding change in its cost. More advanced variations of the retail method, including the dollar-value LIFO retail method, refine the basic cost-ratio approach to address some of these limitations, particularly for retailers managing inventory across many different product categories or price points at once.

A retailer’s cost ratio is not fixed permanently; it shifts whenever the overall markup earned on newly purchased goods changes, whether through supplier price increases, deliberate changes in the retailer’s own pricing strategy, or a shift in the mix of higher-markup versus lower-markup products being purchased. Because the ratio is recalculated using the specific combination of beginning inventory and purchases for each period, a retailer effectively gets a fresh, period-specific cost ratio each time, rather than relying on a single rate assumed to hold indefinitely.