Quick answer
For a #10 wood screw, use a 9/64 inch straight bit in hardwood or a 1/8 inch straight bit in softwood. With tapered bits, use 13/64 inch for hardwood or 3/16 inch for softwood.
Hardwood straight bit
9/64 in
Softwood straight bit
1/8 in
Hardwood tapered bit
13/64 in
Softwood tapered bit
3/16 in
When #10 screws need a pilot hole
#10 screws are large enough that pilot holes are usually worth drilling, especially in hardwood, deck boards, studs, and cabinet parts.
Countersink size
A 7/16 inch countersink is a common match for a flat-head #10 wood screw.
Useful tools for this job
A countersink bit set that includes #10 sizing is useful for furniture, framing hardware, and shop projects.
Frequently asked questions
Can I use 1/8 inch for a #10 screw?
Yes in many softwoods. For hardwood, 9/64 inch is a better straight-bit starting point.