Gross Margin Return on Investment Calculator (GMROI)
Gross margin generated for every riyal invested in inventory.
Combines profit and turn into one number — the gold standard for evaluating buying performance.
- Formula
- Gross Margin SAR ÷ Average Inventory Cost
- Benchmark
- Above 2.50 is strong; below 1.00 means inventory isn't earning its keep
Worked example
- Gross margin (SAR)
- 60,000 SAR
- Avg inventory at cost
- 25,000 SAR
- Result
- 2.40x
How to read it
GMROI is the return on the cash you have parked in stock. A result of 2.40 means every riyal of inventory at cost returned SAR 2.40 of gross margin over the period. Below 1.00 the stock is not covering the margin it consumes. Compare it only within a category — a jewellery counter and a dairy fridge have completely different profiles, and ranking them against each other tells you nothing.
Common mistake
Valuing the inventory at retail instead of at cost. The denominator has to be the cost value of average stock; using retail inflates it by your entire markup and drags every GMROI below its real figure. The other half of the same mistake is taking a single month-end stock number instead of an average — one count taken the week after a big delivery will distort the result on its own.
What to do about it
A low GMROI has only two levers: the margin you make, or the speed you sell. Work out which one is broken before you act. If margin is healthy and the number is still low, you are holding too much — cut the buy depth or the range. If stock is moving and the number is still low, you are buying badly or discounting too hard. Moving both at once is rare; pick the one your category can actually shift.
Questions
What is a good GMROI?
Above 2.50 is strong in most retail categories, and below 1.00 means the inventory is not paying for itself. Grocery runs much higher on fast lines, specialty and fashion lower. Judge it against your own history and the categories beside it rather than an industry number.
Is GMROI better than inventory turnover?
They answer different questions. Turnover tells you how fast stock moves; GMROI tells you what that movement earns. A line can turn quickly on a thin margin and still be a poor use of cash. GMROI is the one to use when you are deciding where to put the open-to-buy.
Should GMROI use gross margin in riyals or as a percentage?
Riyals. The formula divides a margin value by an inventory value, so both sides have to be amounts. Putting a percentage on top produces a number that looks plausible and means nothing.