Calculator · Joinery & fasteners
Wood Screw Length Calculator
The free Wood Screw Length Calculator answers one question: Right screw length for joining two boards. Enter your numbers in inches or millimeters and the result updates instantly in your browser, with no sign-up and no app to install. Use it on your phone at the bench, then copy or print the result for your cut list.
Aim for at least two thirds of the screw's threaded length in the bottom piece.
Which other joinery & fasteners calculators help with this project?
- Pilot Hole Size Calculator — Drill bit sizes for wood screws.
- Nail Size (Penny) Calculator — Penny size and length for your board.
- Biscuit Size Calculator — Which biscuit (#0, #10, #20) for your stock.
- Dovetail Spacing Calculator — Even tail and pin layout for hand-cut dovetails.
- Pocket holes vs. dowels vs. biscuits — Related guide
What you'll need for this project
Tools
Screws & hardware
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Build it · Beginner · Half a day
Download the complete plan with cut list and materials list (PDF)
Screw Chart + Cedar Planter Box — A printable screw length chart plus a simple screwed cedar planter. Drawings, cut list with board-foot totals, hardware list and step-by-step instructions.