The constant gross-margin percentage NRV method allocates joint costs to joint products produced during the accounting period in such a way that each individual product achieves an identical gross-margin percentage. The method works backward by first computing the overall gross margin. Then, for each product, the gross-margin percentage and any separable costs are deducted from the final sales value of production to back into the joint-cost allocation for that product. Exhibit 17-7, Panel A, shows the three steps for allocating the $400,000 joint costs between buttercream and condensed milk in the Farmland Dairy example using this method. Refer to the panel as we describe each step.

The spreadsheet shows two panels depicting the data for the products buttercream and condensed milk.
Panel A: Allocation of joint costs using net realizable value method: Step 1
Final sales value of total production during accounting period (sum of 20,000 gallons multiplied by $25 per gallon and 50,000 gallons multiplied by $22 per gallon): $1,600,000
Deduct joint and separable costs (sum of $400,000, $280,000, and $520,000): 1,200,000
Gross margin: $400,000
Gross margin percentage ($400,000 divided by $1,600,000): 25%
Panel A: Allocation of joint costs using net realizable value method: Step 2
Final sales value of total production during accounting period
Buttercream (product of 20,000 gallons and $25 per gallon): $500,000
Condensed milk (product of 50,000 gallons and $22 per gallon): $1,100,000
Total: $1,600,000
Deduct gross margin, using overall gross-margin percentage
Buttercream (25% of $500,000): $125,000
Condensed milk (25% of $1,100,000): $275,000
Total: $400,000
Total production costs
Buttercream: $375,000
Condensed milk: $825,000
Total: $1,200,000
Panel A: Allocation of joint costs using net realizable value method: Step 3
Deduct separable costs
Buttercream: $280,000
Condensed milk: $520,000
Total: $800,000
Joint costs allocated
Buttercream: $95,000
Condensed milk: $305,000
Total: $400,000
Panel B: Product-line income statement using constant gross-margin percentage NRV method for May 2017
Revenues
Buttercream (12,000 gallons multiplied by $25 per gallon): $300,000
Condensed milk (45,000 gallons multiplied by $22 per gallon): $990,000
Total: $1,290,000
Joint costs of goods sold (from panel A)
Buttercream: 95,000
Condensed milk (0.725 multiplied by $400,000): $305,000
Total: $400,000
Cost of goods sold: Separable costs
Buttercream: $280,000
Condensed milk: $520,000
Total: $800,000
Cost of goods sold: Production costs
Buttercream: $375,000
Condensed milk: $825,000
Total: $1,200,000
Cost of goods sold: Deduct ending inventory
Buttercream (8,000 gallons multiplied by $18.75 per gallon): $150,000
Condensed milk (5,000 gallons multiplied by $16.50 per gallon): $82,500
Total: $232,500
Total cost of goods sold
Buttercream: $225,000
Condensed milk: $742,500
Total: $967,500
Gross margin
Buttercream: $75,000
Condensed milk: $247,500
Total: $322,500
Gross margin percentage
Buttercream ($75,000 divided by $300,000): 25%
Condensed milk ($247,500 divided by $990,000): 25%
Total ($322,500 divided by $1,290,000): 25%
Note 1: Total production costs of buttercream divided by Total production of buttercream equals $375,000 divided by 20,000 gallons equals $18.75 per gallon.
Note 2: Total production costs of condensed milk divided by Total production of condensed milk equals $825,000 divided by 50,000 gallons equals $16.50 per gallon.
Exhibit 17-7, Panel B, presents the product-line income statement for the constant gross-margin percentage NRV method.
The constant gross-margin percentage NRV method is the only method where products can receive negative allocations. This may be required to bring gross-margin percentages of relatively unprofitable products up to the overall average. The constant gross-margin percentage NRV method is also the only method that allocates both joint costs and profits—the same gross-margin percentage is allocated to each product to determine the joint-cost allocations. Neither the sales value at splitoff method nor the NRV method takes account of profits earned either before or after the splitoff point when allocating joint costs.