Cross-Merchandising Calculator

Cross-merchandising pairs a primary product with a related accessory or add-on item -- batteries next to flashlights, wine next to cheese -- and this calculator measures whether that pairing is actually earning its shelf space. Attach Rate is the core metric: it is Attached Item Sales divided by Primary Item Sales, expressed as a percentage, showing what share of primary-product buyers also picked up the paired item. Attached Item Revenue is simply the number of attached units sold multiplied by their price, and Incremental Profit applies a standard 45% margin assumption to that revenue -- a common rule-of-thumb margin for accessory and add-on categories, though your actual margin will vary by product.

Display ROI then compares that incremental profit against Display/Setup Cost -- the cost to build, stock, and maintain the cross-merchandising display or end-cap -- so a positive ROI means the display paid for itself and then some, while a negative ROI means the display cost more than the incremental profit it generated. This calculator isolates the cross-merchandising effect by treating all Attached Item Sales as incremental (driven by the pairing) rather than sales that would have happened anyway through the item's normal shelf location -- in practice, some portion of attach sales may be cannibalized from elsewhere in the store, so treat the calculated ROI as an upper bound and validate with a true test-versus-control comparison when possible. Use it to compare candidate pairings, prioritize which cross-merchandising displays to fund, or evaluate whether an existing display is still worth the shelf space it occupies.