Enter the total depth of the store and the radius of customer attention into the calculator to determine the optimal product placement. This calculator can also evaluate any of the variables given the others are known.

4-9-4 Rule Formula

The following formula can be used to calculate the optimal product placement according to the 4-9-4 rule.

OPP = (D / 4) + (R / 9) + (D / 4)

Variables:

  • OPP is the optimal product placement (feet)
  • D is the total depth of the store (feet)
  • R is the radius of customer attention (feet)

To calculate the optimal product placement, divide the total depth of the store by 4. Then divide the radius of customer attention by 9. Add these two results together, then add the result of dividing the total depth of the store by 4 again. This will give the optimal product placement according to the 4-9-4 rule.

What is a 4-9-4 Rule?

The 4-9-4 rule is a guideline in the field of visual merchandising, particularly in retail store layouts. It suggests that customers tend to walk 4 feet into a store before noticing anything, then they notice items within a 9 feet radius, and finally they tend to walk 4 feet from the last point of interest before noticing something new. This rule is used to strategically place products and displays to capture customer attention and maximize sales.

How to Calculate 4-9-4 Rule?

The following steps outline how to calculate the optimal product placement (OPP) using the 4-9-4 Rule.


  1. First, determine the total depth of the store (D) in feet.
  2. Next, determine the radius of customer attention (R) in feet.
  3. Next, use the formula OPP = (D / 4) + (R / 9) + (D / 4) to calculate the optimal product placement.
  4. Finally, calculate the OPP.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

Total depth of the store (D) = 40 feet

Radius of customer attention (R) = 15 feet