Plywood Layup Calculator for veneer stacks. Enter the ply count, veneer thicknesses and panel size to see the pressed thickness, the balance, glue use, press force and wood weight.
Plies alternate grain 90°. Face and back use the face veneer; every ply between them uses the core ply.
Press, Glue and Wood
Coverage is per glue line. Target thickness drives the ply table below the results.
Layup Stack and Ply Table
Light plies run along the face grain, dark plies across it. Not to scale.
| Ply Count | Thickness | Along Grain |
|---|---|---|
| 3 plies | 0.256 in | 50% |
| 5 plies (yours) | 0.512 in | 50% |
| 7 plies | 0.768 in | 50% |
| 9 plies | 1.024 in | 50% |
| 11 plies | 1.280 in | 50% |
| 13 plies | 1.536 in | 50% |
| 15 plies | 1.792 in | 50% |
| 17 plies | 2.048 in | 50% |
| 19 plies | 2.304 in | 50% |
| 21 plies | 2.560 in | 50% |
Plywood Layup Calculator for Shop-Made Veneer Panels
Making plywood from loose veneer means planning a stack before any glue is spread. Pick how many plies, how thick each one is and how the grain turns, then work out the thickness, glue, pressure and weight that stack will give you. This tool does that planning for furniture makers pressing their own panels, drum makers forming shells from 2 and 3 ply sheets, and anyone laying up a skateboard deck in a vacuum bag.
Enter the ply count, the face veneer thickness and the core ply thickness in inches, plus the panel size. Face and back use the face veneer, and every ply between them uses the core thickness. Glue, press method, vacuum level and species sit in the accordion below the main inputs.
Pressed thickness is the wood plus a thin layer of cured glue at every joint. Two face veneers, the core plies between them and one glue line per joint add up to the total.
Here f is the face veneer, c is the core ply, n is the ply count and g is the cured glue line. With the defaults, 1/16 inch faces around three 1/8 inch cores press to about 0.512 inch. The glue line is the tool's own 0.003 inch assumption, and you can set it to zero to see wood alone.
The Layup Stack and Ply Table shows the stack as a drawing and lists what 3 to 21 plies of the same veneers would give. For a 3/4 inch target with these plies, 7 plies at 0.768 inch comes closest.
Balance Matters More Than the Ply Count
A panel stays flat when the plies above its center mirror the plies below. The Hardwood Plywood and Veneer Association standard, ANSI/HPVA HP-1-2024, says most panels get there with an odd number of plies, where every inner ply except the innermost comes in a matched pair.
That is why the first card calls an odd stack balanced. With strict alternation, an even stack puts a long-grain ply on one face and a cross-grain ply on the other, so the two sides pull differently as moisture changes.
Even counts can still work. A USDA Forest Service plywood overview describes four-ply panels whose two center plies are glued with parallel grain, so they act as one center layer. A Sawmill Creek member puts the rule plainly: whatever the count, each ply should match its counterpart counted out from the center.
The first card also shows how much of the wood runs along the face grain. With equal plies alternating, that share stays near half no matter how many plies you add, so the panel is almost as stiff one way as the other.
Skateboard Decks Don't Alternate Every Ply
A 7-ply skateboard deck is laid up differently from furniture plywood. Marwood Veneer, which sells deck veneer, puts face grade on layers 1 and 7, core on layers 2, 4 and 6 and crossband on layers 3 and 5. Only the two crossbands run across the deck.
So a deck of equal 1/16 inch plies has five long-grain plies out of seven, about 71% of its wood along the length. Marwood credits the long-grain layers with the board's flex and the crossbands with its stability. Roarockit, another deck veneer supplier, likewise tells builders to keep the cross-grain sheets near the middle of the stack with one core layer between them.
The deck is still balanced, since layers 1 to 3 mirror layers 5 to 7. For thickness, the Plywood Layup Calculator gives the same answer either way, about 0.456 inch for seven 1/16 inch plies and six glue lines.
Vacuum Pressure, Altitude and Glue Choice
A vacuum bag presses with the air outside it. Each inch of mercury on the gauge equals about 0.491 psi, one atmosphere of 14.7 psi divided by 29.92 inches.
At the default 25 inHg that is about 12.3 psi. On a 24 × 48 inch panel it adds up to roughly 7.1 tons spread evenly across the face, which the third card reports.
Altitude caps what a pump can pull. VeneerSupplies.com notes a loss of about 1 inHg per 1,000 feet, so a system that reaches 25.5 inHg at sea level manages about 20.5 inHg at 5,000 feet. The same page gives 17 inHg as the usual minimum for veneer and 21 inHg for species such as maple.
Glue ratings are where makers and shops disagree. Titebond's data sheet asks 100 to 250 psi for Cold Press for Veneer, far beyond any vacuum bag. Yet members of the LumberJocks forum report pressing gallons of it at about 10 psi without trouble.
The tool warns you when the bag falls short of the glue maker's rating, so you can decide with both facts in view. Unibond 800 avoids the question, since Vacuum Pressing Systems formulated it as a room-temperature urea glue for their VacuPress. Highland Woodworking lists it at about 45 minutes of open time at 70°F and not for use below 70°F.
For a clamp and caul press, the third card turns the glue maker's minimum pressure into total press force. The Clamp Pressure Calculator helps space clamps to reach it.
Glue Quantity and Panel Weight
Every joint between plies is a full-size glue line, so a 5-ply panel has four. On the default 24 × 48 inch panel that is 32 square feet of glue area, about 18.2 fluid ounces at Unibond's 225 square feet per gallon.
Q is the glue in gallons, A is the panel area in square feet and C is the coverage. Vacuum Pressing Systems puts Unibond 800 at 200 to 250 square feet per gallon depending on porosity, and Titebond lists Cold Press at about 250. Coarse veneer drinks more. One WOODWEB shop pressing coarse 1/16 inch white oak reported rolling out almost three times the suggested amount.
The fourth card estimates weight from the wood alone. It uses the species' specific gravity at 12% moisture from the Wood Handbook and density equal to that gravity times 62.4 times 1.12.
The default yellow birch panel holds 0.333 cubic feet of wood, about 14.4 pounds. Glue adds a little more. The Wood Weight Calculator covers solid boards the same way.
When a Pressed Panel Goes Wrong
Why did my panel warp after it came out of the press?
Often it is the drying, not the layup. On the Fine Woodworking forum, one maker stacked fresh panels on stickers and found the top panel cupped, because its upper face dried freely while the others were covered.
A WOODWEB veneer forum member who presses with Titebond II in a vacuum press says the same. Panels left with one face drying faster, from sunlight or a nearby heater, warp. Stand fresh panels on edge or sticker them so air reaches both faces equally.
Can I veneer only one side of a panel?
It unbalances the panel. The same Fine Woodworking thread points out that commercial plywood always uses a back veneer of the same thickness as the face to equalize stress.
Add a backer that matches the face veneer's thickness and grain direction, even on a side nobody will see. Count both in Number of Plies so the tool includes every glue line and flags any imbalance.
How many plies make a 3/4 inch panel?
That depends on the veneer. With the default 1/16 inch faces and 1/8 inch cores, 7 plies reach about 0.768 inch. Baltic birch at 18 mm uses 13 thinner plies, a count confirmed by Woodcraft and by Sawmill Creek members.
The Baltic Birch 18 mm starting point uses 13 plies of 1.3 mm each and lands near 17.8 mm with glue. Measure your own veneer with calipers before trusting any count, since sliced and rotary veneers vary. When the panel is done, the Plywood Cut List Calculator plans the parts you cut from it.