Memory Foam Tip: Memory foam density is one measure of how much support or cushion the memory foam will provide. The higher the density, the greater the density or weight of the memory foam. In general, the higher the density, the greater the support and memory foam feeling and the higher the price. Most products you'll see are in the 3 pound to 5 pound range. Memory foam experts recommend that a memory foam density of about 4 pounds gives good price to performance. A density of under 3 or 3.5 pounds may not have the effect you seek. A density of over 5 pounds may have you paying more for a difference in responsiveness and be too stiff to be comfortable.