How Do You Calculate Inventory Velocity for Ecommerce?

September 26, 2016
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Calculating Inventory Velocity for Ecommerce Stores

It’s a delicate balance for online store owners, keeping enough merchandise in stock to meet customer demand but not too much that you’re tying up capital and inventory space. The ability to improve inventory turnover, or velocity, can help you achieve this balance and contribute to the profitability of your ecommerce store.

Why is Inventory Velocity Important?

Inventory turnover can be one of the most important financial ratios for store owners to monitor and manage. It measures the liquidity of your inventory and can help you determine how to increase sales through inventory control.

Put simply, ecommerce stores with high turnover are selling inventory faster. That means less cash tied up by the company. Stores with low inventory velocity may be holding obsolete inventory that is difficult to sell, which erodes company profits.

How to Calculate Inventory Velocity    

By calculating your inventory velocity, you can measure and improve how your ecommerce store is controlling and selling merchandise. You can determine velocity by dividing the cost of goods sold by the average inventory for the period you are measuring.    

Inventory Turnover Ratio = Cost of Goods Sold / Average Inventory        

With all ecommerce store owners have to keep track of, it’s easy to overlook the hidden costs of inventory that’s not turning over, including space, insurance, taxes and capital costs. A regular calculation of inventory turnover can help online retailers focus on reducing overhead costs and improving velocity.    

Metrics that Impact Inventory Turnover

1. Planning Cycle Time        

This is the time between the signal of customer demand and releasing an order to the supplier. A high variability in cycle time can have a negative impact on the your inventory flow. The goal is to simplify your communications and processing with suppliers to reduce lead time as much as possible.    

2. Supplier Lead Time    

This represents the time lag on the supplier end between receiving the purchase order and shipping the order. Ecommerce store owners can improve this by quickly responded to changes in demand.

3. Variability of Demand    

Measuring variability of demand can help you segment your inventory and determine which type of reorder policy to use. For example, for products with consistently high demand you may want to use a schedule ­based order process. For items with low demand, it’s better to order on an as­needed basis, rather than keeping the products in stock.

Improve Inventory Velocity with Accurate Purchase Order Timing

In addition to the metrics above, online store owners should track the following data points to make accurate predictions on when to reorder merchandise. Getting the timing right on ordering and replenishing will further improve your inventory turnover rates.    

Quantity Sold

At any given time, you should be able to view the number of items you have sold in each product category. Viewing this data for a selected date range enables better inventory decision making.    

Quantity Left

By pulling data from your ecommerce platform you should be able to see the number of products remaining in your inventory. It’s critical to follow this metric closely to avoid out of stock items and lost sales.

Depletion Days

If you know how many days until your stock will be depleted, you can place your reorders with confidence. This metric is based on the quantity available divided by velocity, which determines, on average, the number of days left until the product will be out of stock.

Lead Time

Lead time is the amount of time it takes your supplier to deliver goods once you have placed a reorder request. Keep track of the average lead time from each of your suppliers to plan future orders accordingly.

Glew Offers a Unique View of Inventory

Glew transforms your ecommerce store’s Merchandise sales data from difficult to analyze silos of data into revenue generating opportunities. Understand product Highlights, such as most profitable products or best bundles, and drill down to Individual Product Pages to learn more about what’s helping or hurting your store’s performance. Glew’s Highlights include over 20 out-of-the box segments that will provide you with granular levels of information needed to optimize your store’s sales strategy.

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