The versatility of gross profit margin
You may know the gross profit margin ratio, which is:
Gross Profit x 100
Gross profit is: Sales – Cost of Sales
Cost of Sales = Opening inventory + Purchases/cost of production – Closing Inventory.
In this short post I would just like to share some of my experiences on the versatility of this simple ratio. If we look at the elements of the ratio, it is easy to see that if each element remain stable, the answer should also be stable. So for example, if I buy something for €40, sell it for €100, then my GP margin is 60%. If my sales price or purchase price changes, then the GP margin changes. Then, if we think about inventory levels, if these fluctuate the GP margin changes too. Taking all this together, it’s easy enough to see how any business typically knows what its GP margin should be. Thus, if it varies considerably, there may be something wrong.
Here are two things I know the GP margin is used for. One, from my own experience, is in pubs/bars. Most pubs/bars are susceptible to fraud and controls typically put in place by owners. One such control is monthly stock-takes and monthly accounts. A fall in the GP margin could indicate “lost” stock or unrecorded cash receipts – which further controls may reveal. Another use is to spot inflated revenues. Businesses may want to make their profits look better and thus do things like invoice for goods early, before the end of a financial year. These good may not even be bought/made yet. Thus, the GP margin may be lower. Again further investigation is needed to find the issue.
There may of course be more simple reasons for changes in the GP margin – costs and sales prices may simply change and affect the ratio. But once these have been ruled out, it is a useful indicator.