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📏 Screw Length Calculator

Calculate the correct screw length for your project

Material & Application Details

💡 General Guidelines:

Wood: Screw should penetrate 2/3 to 3/4 of base material thickness

Metal: Penetrate at least 2x the screw diameter

Drywall: Penetrate at least 5/8" into stud

Countersunk heads: Add depth for countersink (typically diameter of screw)

Recommended Screw Length

Visual Breakdown

Top Material Base Material Top Penetration Total

Common Screw Length Guidelines

Application Material Thickness Typical Screw Length Notes
3/4" Wood to Wood 3/4" 1-1/2" to 2" Standard cabinet work
1/2" Drywall to Stud 1/2" 1-1/4" Minimum 5/8" into stud
5/8" Drywall to Stud 5/8" 1-5/8" For thicker drywall
2x4 to 2x4 1-1/2" 3" Framing applications
Deck Boards 1" to 2x6 2-1/2" to 3" Outdoor deck screws
Plywood to Stud 3/4" 1-5/8" to 2" Subfloor or sheathing

Countersink Depth Reference

Screw SizeCountersink Depth
#60.138" (approx. 9/64")
#80.164" (approx. 11/64")
#100.190" (approx. 3/16")
#120.216" (approx. 7/32")
1/4"0.250" (1/4")