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Reviewed by CA Nikhil Gupta · Last reviewed 11 October 2026
Compare category-level gross margin return on average inventory at cost, stock turns and portfolio profitability using a reconciled retail cost bridge.
Modify every assumption; the initial numbers demonstrate the method, not observed market rates.
Compare category-level gross margin return on average inventory at cost, stock turns and portfolio profitability using a reconciled retail cost bridge. This is an offline browser-side scenario estimator for professional planning, not an automatic legal, accounting or tax determination.
Gross margin return on inventory investment measures how many rupees of gross profit a store generates for each rupee of average stock carried at cost over a stated period. For instance, a GMROI of 1.20 means ₹1.20 of period gross profit for each ₹1 of average inventory cost; it does not mean a 120% net profit margin or a risk-free investment return. The metric is useful when comparing product categories that have different prices, gross margins and inventory commitments. It complements, rather than replaces, cash-flow and stock-availability analysis.
Start with sales net of returns and agreed sales discounts. Deduct the cost of goods sold associated with those net sales to calculate gross profit. Next compute average stock held at cost. The simple method used here takes the mean of opening and closing inventory book cost for each category, although a monthly average is often preferable for seasonal categories. Sales, COGS and inventory must cover the same merchandise perimeter. Mixing net sales from several stores with stock held by one store makes the ratio unreliable. Do not use ticket retail prices as inventory cost.
For multiple categories, first sum gross profit and average inventory cost, then divide. GMROI at the portfolio level is a capital-weighted outcome; averaging the category ratios gives disproportionate influence to categories with tiny stock commitments. The table exposes each category’s cost denominator, sales, cost of sales, gross margin and GMROI. Negative gross profit is permitted so loss-making categories are visible. If all categories have zero average stock, the aggregate return is undefined. Examine those exceptions before comparing store managers or product groups.
Cost-based inventory turns divide the same-period cost of goods sold by average inventory at cost. When a reporting period spans 365 days, implied stock days approximate 365 divided by turns, provided turns are positive. These stock days are a simplified interpretation, not a forecast of every product’s sell-through date. High turns may arise from efficient inventory discipline or chronic understocking; low turns may reflect seasonal build-up, long lead times, warranty buffers or slow-moving items. Always combine the result with availability, aged-inventory and service-level data.
The sample holds footwear, accessories and clothing categories. Their net sales total ₹54,00,000 and COGS total ₹33,90,000, leaving ₹20,10,000 of gross profit. Average stock at cost is ₹16,75,000, calculated from each category’s opening and closing cost figures. Portfolio GMROI is consequently 1.20×, and the period cost-based turns are approximately 2.02×. The user also enters ₹1,10,000 fixed operating costs, producing a simple operating surplus of ₹19,00,000. That last figure excludes other unentered variable or period expenses and is not an audited EBIT.
A markdown affects sales revenue when an item is actually sold at the lower price; it does not necessarily change its accounting inventory cost. Returns can reverse both revenue and related COGS if the goods can be resold, but damaged returns may need separate loss treatment. Inventory write-downs, shrinkage and purchase-cost adjustments need consistent bookkeeping and management policies. If the cost of returned goods has not been reversed in your COGS input, the model will understate gross profit. If stock is held on consignment, establish which legal entity carries the balance sheet investment before including it.
Retail reporting periods may be calendar months, quarters or full years. A GMROI of 0.8 for a quarter and 1.5 for a year are not directly interchangeable; period length and assortment composition can dominate the comparison. The calculator accepts reporting days to interpret inventory turns in equivalent days, but does not annualise GMROI automatically. For festive-season sellers in India, track monthly stock snapshots across Diwali or other campaign periods rather than only comparing opening and closing points. Document the exact date and store perimeter behind each source dataset.
Prioritise categories with a large stock investment and weak GMROI, but investigate why before reducing stock. A category may have high return potential but require a broad size or colour range that cannot be optimised by a single ratio. Separate frequent movers, long-tail assortment and seasonal safety stock. Check whether suppliers allow returns or stock swaps, whether forecast errors are high, and whether the average selling price is sustainable. Measure the impact of smaller replenishment lots against freight, stockout and minimum-order costs rather than assuming every stock reduction is free.
This is a management analytics calculator, not an inventory valuation or statutory tax engine. Different businesses capitalise purchase expenses differently; opening and closing values should be consistent with the company’s inventory accounting policies. It does not compute GST liability, income-tax deductions, Ind AS 2 net realisable value, or return on working capital after financing. The formula and terminology are explained in the cited specialist retail reference; operational data still need independent reconciliation to POS, purchases and inventory ledgers. Each result must be reviewed with its assumptions clearly recorded.
No. GMROI divides gross profit by average inventory held at cost; gross margin percentage divides it by revenue.
GMROI and cost-based stock turns are undefined, not infinite or automatically zero.
Not arithmetically. Portfolio GMROI uses total gross profit divided by total average inventory at cost.
No. The denominator must use inventory at cost, with consistent treatment of write-downs and returns.
Sources explain the calculation conventions and rules referred to above. Notifications and standards change; confirm on the official site before you file, book or advise.
Educational working tool. Results follow the scope and assumptions described on this page and the figures you enter; they are not accounting, audit, tax, legal, investment or financing advice. Treatment depends on facts, contracts and the law or standard in force for the relevant period, so reconcile to your records and consult a qualified professional before you rely on a result.
Background, worked examples and the rules behind these numbers.