Below is a formula from Toyota you can use to make an informed decision.
1. Start with the basic right-angle stacking width
2. Add the load length
3. Add 12 inches for clearance
The basic right-angle stacking width is the smallest amount of space a forklift needs turn in order to insert its forks into a pallet. You can find basic right-angle stack measurements in the equipment manual or by contacting TMHNC if your business is located in Northern California. This measurement does not include the length of the load or room need for clearance.
Load lengths vary depending on your application, products, etc. As a starting point, a standard pallet has a 48- inch load length. Always check your forklift's data plate for the rated capacity (which is affected by attachments and other factors).
Adding 12 inches for clearance ensures you have enough room for your forklift's turn radius and helps protect against damage from operator error and/or product that may hang over the edge of the pallet.