Inventory finance
Stock-to-Sales Ratio
By the Supply Chain Manager team · Updated October 16, 2026
The stock-to-sales ratio compares inventory value at the start of a period with sales in that period, showing how much stock supports each dollar of sales.
A ratio of 3 means you hold three times a month's sales in stock. It is common in retail planning and useful for comparing categories or tracking whether stock is growing faster than sales.
The ratio is a simple warning light. If it climbs for several months while sales are flat, stock is building somewhere, and the next step is to look at SKU-level days of supply to find where. On its own it does not say which items are the problem.
How to calculate stock-to-sales ratio
Stock-to-Sales Ratio = Inventory value at start of period ÷ Sales value for the period
Stock-to-sales ratio example
Illustrative numbers: $450,000 of stock at the start of the month and $150,000 of sales in that month give a ratio of 3. If sales stay flat and the ratio rises to 4 a few months later, stock is building faster than demand.
Why stock-to-sales ratio matters for distributors
It is a quick, high-level check that inventory is growing in step with the business rather than ahead of it.
Common stock-to-sales ratio mistakes
- Mixing inventory at cost with sales at retail price, then comparing with ratios calculated the other way.
- Using it for seasonal categories without adjusting for the season.
Examples on this page use made-up round numbers to show the calculation. They are not benchmarks or results from real businesses.