The Mysterious Cost
of Carrying Inventory

by Jon Schreibfeder


The carrying cost of inventory is the cost of maintaining your average inventory investment of inventory in your warehouse, storeroom, stockroom, or other location where you stock raw materials or finished goods. What costs do you incur in carrying inventory?

The carrying cost percentage is calculated by dividing the sum of these expenses (along with the opportunity cost) by the average inventory value. It is the amount of money it takes to maintain one dollar's worth of inventory for an entire year.

For years many industry consultants have maintained that determining your company's actual carrying cost is too difficult to calculate in a reasonable amount of time, and that you should use a rule of thumb such as "current prime rate plus 20%." One inventory "guru" recently suggested that you should adjust your carrying cost percentage so that the economic order quantity formula suggests "reasonable" reorder quantities.

This is backwards thinking. The economic order quantity formula is designed to calculate the lowest total cost reorder quantity (i.e. your "best buy quantity") based, in part, on the cost of carrying inventory. If it costs you less to maintain inventory in your warehouse, you will tend to stock more. If your carrying costs are high, you will probably want to keep just enough inventory in your warehouse to protect customer service. Guessing at your carrying cost will not ensure that you are buying the quantity that will minimize your firm's total cost of inventory.

Just as important, using an approximate carrying cost does not help you identify areas for potential improvement in your warehouse operations. In these days of increased competition, lower margins, and greater customer demand of product availability, it is important to lower operating costs and increase productivity wherever possible. By closely examining the specific components of the inventory carrying cost and comparing the numbers to other firms in your industry and region, you can identify areas that are candidates for improvement.

With all of this in mind, EIM would like to help you calculate your cost of carrying inventory. If you will print and fill out the attached questionnaire and send it to us by email, mail, or fax, we will calculate your carrying cost and send you a comparison of your answers to each question to others in your region and industry. There is no charge for this service as long as you agree to let us add your information to our database. Please note that all responses are confidential. Data we present to other companies will not identify your company name or location.

Even if you don't fill out the questionnaire, please review it, as it includes most (if not all) of the factors you must consider as you calculate your own inventory carrying cost.


Questionnaire for Calculating
Carry Cost of Inventory

Complete for each stocking facility. Please contact us with any questions.
Send the completed questionnaire to:

Effective Inventory Management, Inc.
215 South Denton Tap Road, Suite 230
Coppell, TX 75019 USA
Phone: (972) 304-3325
Fax: (972) 393-1310
Email: carrycost@effectiveinventory.com

Your Name _____________________________________________________________
Company _______________________________________________________________
Address _______________________________________________________________
City _____________________  State/Prov ____________  Postal Code ______
Phone _____________________________  Fax ______________________________
Email _________________________________________________________________

Distributor/Manufacturer/Retailer ______________________________
Types of Products Sold _________________________________________

We will only contact you with the results,
or if we have questions concerning your answers.


  1. What was your average inventory value over the past 12 months (sum of month-ending inventory values divided by 12)? _______

  2. What was your total warehouse labor expense (wages, taxes, and benefits) during the past 12 months (including the expense of inspection, putting away stock, moving from bin to bin as necessary, assembling kits, and filling customer orders)? _______

  3. What percentage of warehouse activity is dedicated to filling customer orders and transfers? _______

  4. Is this warehouse owned or rented? _______

  5. If the warehouse is rented, what is the monthly rent? _______

  6. If the warehouse is owned, what is the rental cost of comparable warehouse space under a "triple net" lease (i.e. a lease where the tenant pays all utilities, maintenance, and property taxes)? _______

  7. How many square feet (or meters) is your facility? _______

  8. How many square feet (or meters) is your warehouse? _______

  9. What were the total warehouse utilities you paid last year? _______

  10. What were the total property taxes you paid last year? _______

  11. What was your total warehouse maintenance expense last year? _______

  12. What was your total warehouse supply expense, excluding shipping materials (that is, storage boxes and other supplies used in the process of receiving and stocking material)? _______

  13. What was the cost of warehouse equipment that was expensed (i.e. not capitalized) last year? _______

  14. What was your total depreciation expense for warehouse equipment last year? _______

  15. What was the value of written-off inventory last year? _______

  16. What was the value of inventory shrinkage last year (not included in the written-off inventory value)? _______

  17. How much current inventory is in excess of a 12-month supply (a value equal to monthly demand x 12)? _______

  18. What was the cost of insuring your warehouse and equipment last year? _______

  19. What was the cost of insuring your inventory last year? _______

  20. What was the cost of any inventory taxes you paid last year? _______

  21. If additional labor was necessary to conduct physical counts of your inventory, what was the cost of this labor (including taxes and benefits)? _______

  22. If you borrow money to finance your inventory, what was the average outstanding balance over the past 12 months? _______ What is the annual interest rate? _______

  23. If you borrow money to finance warehouse equipment or improvements, what was the average outstanding balance over the past 12 months? _______ What is the annual interest rate? _______

  24. If you finance your own inventory purchases, what interest rate could you expect to receive if you invested that money in a relatively safe income-producing investment? _______


Please use this information to calculate an inventory carrying cost for our company. We agree to allow Effective Inventory Management, Inc. (EIM) to use this data for comparative purposes, but acknowledge that EIM will not reveal our company name or location to any other party without our expressed written permission.


______________________________________________________________
Signed by Company Representative

______________________________________________________________
Print Name, Title, and Date

Next Article: Consider if Some Inventory Will Need To Be Buried


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Effective Inventory Management, Inc.
215 South Denton Tap Road, Suite 230
Coppell, TX 75019
(972) 304-3325
Fax: (972) 393-1310
Email: info@effectiveinventory.com