How Shopify merchants use GMROI
The ultimate efficiency metric-it combines margins and turnover.
Formula
GMROI = (Gross Margin / Average Inventory Cost)
Dividing profit by the cost of stock shows the return on your investment.
What matters in practice
- GMROI > 1.0 means generating more profit than spent on stock.
- Calculated as Turnover × Gross Margin Percentage.
- Aggregating across the store can hide 'cash-trap' SKUs.
Why it matters
Common merchant pain points
- • High-margin slow-movers having lower GMROI than low-margin fast-movers.
- • Failure to account for markdowns when calculating profitability.
Native Shopify limitations
- • Shopify reports do not natively calculate GMROI.
- • Requires blending sales with average stock value manually.
Benchmarks and reference points
A GMROI of 3.2 is an 'excellent' benchmark for retail.
Most retailers aim for >1.5 to cover operating expenses.
How to apply this in practice
Step 1
Find Total Gross Margin
Total Sales minus COGS for a specific period.
Step 2
Find Avg Inventory Cost
Average of your inventory value (at cost) during that same period.
Step 3
Analyze Efficiency
Divide Margin by Cost. A result of 2.0 means every $1 spent on stock made $2 in profit.
Examples
High Margin vs High Velocity
A merchant compares a luxury watch (high margin, low turn) to a battery (low margin, high turn) to see which is a better use of capital.
Vendor Negotiation
A brand uses low GMROI data to demand a lower unit cost from a supplier whose products aren't moving fast enough.
Frequently asked questions
Related resources
Related calculators
- Inventory Turnover Calculator for Shopify | Free Formula + Benchmarks
Calculate your inventory turnover rate and days of inventory (DSI). Use the free Synplex inventory turnover calculator with industry benchmarks and Shopify-specific guidance.
Related glossary terms
- Reorder Point (ROP)
Reorder point is the inventory level at which a new purchase order should be placed so that replenishment arrives before existing stock is depleted.
- Safety Stock
Safety stock is the extra inventory held above expected demand to reduce the risk of stockouts caused by variability in demand or lead times.
- Inventory Turnover
Inventory turnover measures how many times a company sells and replaces its inventory over a given period, typically a year.