How To Calculate The Weight Of Plywood

More than 70 species of wood are used to make plywood. The varied adhesives used in the process weigh more than the wood itself. The combined inconsistency of materials makes plywood weight calculations differ to some degree. But there are generic formulas, and when used as guidelines only, can be used to calculate plywood weight.

Engineers have rounded-off weight calculations for plywood to square foot calculations, and have decided that, for engineering purposes, a generic square foot of 3/4-inch-thick hardwood plywood weighs 2.3 pounds. A 4-by-8 sheet of plywood equals 32 square feet, so 32 times 2.3, is just over 70 pounds per sheet.

Hardwood is more dense than softwood, so a sheet of fir plywood will typically weigh less than a sheet of maple. If you're not sure what you're dealing with, it's always better to estimate on the heavy side, especially when loading multiple pieces on a pickup truck, for example, or estimating the weight for a floor.

The species of plywood can make a difference in weight. The lightest hardwood plywood is typically made with poplar, alder or mahogany. Softwood varieties will typically weigh less than the hardwood varieties, but the lightest plywood of them all is typically pine. If you absolutely have to have the lightest plywood available, special ultralight plywood is also available.

Plywood thicknesses are another issue. Even though you might purchase plywood stated as 3/4-inch-thick, it's likely thinner. Plywood is sized nominally, which is a generic reference to it's thickness. For example, a 3/4-inch piece of plywood may only measure 13/16 inch actual thickness, and therefore weigh slightly less than it's nominal measurement of 3/4 inch.

The square foot weight calculation is different for specific, nominal thicknesses of plywood. For example, 1/4-inch thick Baltic birch plywood is estimated at about .8 pounds per square foot, weighing just over 25 pounds a sheet, while 1/2-inch-thick birch plywood is estimated at 1.5 pounds per square foot, and using the engineering formula, tips the scales at about 48 pounds.

Practical Purposes

It's one thing to do the math and come up with your own calculations, but most cabinetmakers and builders use more simple calculations, determined by a generic weight per sheet. The numbers typically err on the heavy side.

• 3/4 inch: 75 pounds.
• 1/2 inch: 50 pounds.
• 1/4 inch: 25 pounds.

• 3/4 inch: 65 pounds
• 1/2 inch: 40 pounds
• 1/4 inch: 22 pounds

Plywood might not actually be plywood, but actually an engineered product. Lots of cabinets and furniture makers rely on a particle board or MDF — medium-density-fiberboard — and it's heavier than plywood. With a hardwood veneer, MDF has a dense particle board core, and looks just like ordinary plywood. It's much heavier, tipping the scales at between 90 and 100 pounds for a single sheet. If you're not sure if it's MDF or not, examine the side. If you see layers it's plywood. If it's solid it's MDF.

The average half-ton pickup truck can safely haul about 1,000 pounds. A dozen sheets of 3/4-inch softwood plywood weighs about 850 pounds, which, when added to your own body weight is about as many sheets as you can haul safely on a half-ton pickup.