Pocket Hole Screw Length Calculator
Pick the right pocket-hole screw length, drill-guide and collar settings, and thread type from your material thickness and species.
How it works
Screw length from thickness (Kreg chart): 1/2″→1″, 3/4″→1-1/4″, 1″→1-1/2″, 1-1/4″→2″, 1-1/2″+→2-1/2″ · Drill collar = material thickness
A pocket-hole screw has to bury enough thread in the mating piece to hold, without blowing out the far face. The manufacturer’s rule ties screw length to the thickness of the material you drill into: three-quarter-inch stock takes a 1-1/4″ screw, half-inch takes a 1″, and thicker stock steps up from there. Just as important is the jig setup — the drill-guide and the stop-collar on the bit are both set to the material thickness so the pocket bottoms out at the right depth for that screw. Thread type follows the wood: coarse threads bite in soft, low-density material (pine, plywood, MDF) while fine threads hold better in dense hardwoods without splitting them.
Worked example
Joining 3/4″ plywood: the chart calls for a 1-1/4″ screw with a coarse thread (plywood behaves like softwood for grip). Set the pocket-hole jig’s drill guide to 3/4″ and slide the drill-bit stop-collar to 3/4″ as well, so the pocket depth matches the 1-1/4″ screw. In 3/4″ oak you would switch to a 1-1/4″ fine-thread screw instead.
Frequently asked questions
Coarse or fine thread — how do I choose?
Match it to density. Coarse threads grab soft, low-density materials (softwoods, plywood, particleboard, MDF) where fine threads would strip. Fine threads hold better and split less in dense hardwoods like oak, maple and walnut.
What if I’m joining two different thicknesses?
Set the jig and choose the screw for the thickness of the piece you drill the pocket in — that is the board the screw passes through first. Just make sure the screw is not so long it exits the face of the thinner mating piece.
Why set the collar to the material thickness?
The drill guide and stop-collar together fix how deep the pocket sits below the surface. Setting both to the material thickness positions the pocket so the recommended screw reaches well into the joined piece while stopping short of its outer face.
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This calculator is for educational purposes. Double-check important results before acting on them.