Inventory glossary

What is GMROI?

GMROI (Gross Margin Return on Inventory Investment) measures how much gross profit a store earns for every dollar spent on average inventory.

GMROI tells you whether your inventory is pulling its weight, not just whether it sells. A product can have high margins but still be a poor investment if too much cash sits in stock that moves slowly. For a small Shopify store with limited cash, this matters more than almost any other number, because every dollar in excess stock is a dollar not available for new products or marketing.

Use GMROI at the category or product level, not just storewide. Comparing it across SKUs shows which items deserve more shelf space and reorder priority, and which ones are quietly eating your cash. Review it every few months alongside sell-through rate to catch slow movers before they become dead stock.

Formula

GMROI = Gross Margin ($) / Average Inventory Cost ($)

Example

A candle store has average inventory cost of $10,000 over the year and earns $18,000 in gross margin dollars during that time. GMROI = 18,000 / 10,000 = 1.8. For every $1 held in inventory, the store earned $1.80 in gross profit.

Common mistakes

  • Using inventory at retail value instead of cost, which inflates the denominator and skews results.
  • Calculating it once a year instead of by season or category, hiding problem SKUs.
  • Confusing GMROI with gross margin percentage, they measure different things.

GMROI and SteadyShelf

SteadyShelf does not calculate GMROI, but by forecasting demand per variant and sizing reorders to case packs, it helps avoid the overstock that quietly pulls GMROI down.

SteadyShelf is launching on the Shopify App Store. Join early access to get the install link first.

Related terms

Inventory turnover · Gross margin · Carrying cost · Dead stock · Sell-through rate

Full inventory glossary

FAQ

What counts as a good GMROI for a small store?

A margin near 1.0 means every dollar tied up in inventory returns about a dollar of gross profit a year. Below 1.0, the money sitting in stock is earning less than it costs you in capital tied up. Above 2 or 3 is generally strong for most small retailers, but it depends on your category.

Does slow-moving stock hurt GMROI even if it eventually sells?

Yes. Slow-moving SKUs with high stock levels and thin margins drag GMROI down. Finding and clearing those out, or cutting reorder quantities on them, usually improves the ratio faster than trying to raise prices.

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