Bit sizingLess splittingStronger joints
Screw Pilot Calculator
Dial in pilot-hole sizes by screw and species so threads bite hard without blowing out edges. Cleaner drives, fewer splits, better-looking work.
Fast workflow
- Select screw type/size (or enter diameter if supported).
- Choose wood species (softwood vs hardwood matters).
- Read the pilot bit recommendation (and optional clearance/countersink).
- Test on scrap, then commit to the real part.
Tip: If you’re near an edge or end grain, size the pilot slightly larger. It’s cheaper than re-making a stile.
Screw Pilot Hole Calculator
Find the correct pilot and clearance hole sizes for screws in softwood or hardwood applications.
How to use
- Pick your screw size and material type/species.
- Drill the pilot to the recommended diameter.
- If the screw head seats poorly, add a countersink (or use a combo bit).
- Drive one test screw in scrap to validate bite and avoid splitting.
Pro tips
- • Hardwoods usually need a larger pilot than softwoods for the same screw.
- • Near edges: add clearance in the first piece, pilot in the second piece.
- • If you’re seeing split fibers, wax the screw threads or step up the pilot slightly.
FAQs
Why does the same pilot size work in pine but split oak?
Dense hardwoods don’t compress as easily. A pilot that’s fine for softwood can wedge hardwood apart as threads displace fibers. Increase pilot slightly for hardwoods.
What’s the difference between pilot and clearance holes?
A pilot hole is sized for the threads to bite. A clearance hole is sized for the screw shank to pass through the top piece so the screw can pull parts tight.
When should I always countersink?
If you want flush heads, you’re close to an edge, or you’re driving into brittle species, a countersink reduces surface splitting and keeps the head from mushrooming fibers.