HandyToolsHub
Framing & structure

Stud Hole & Notch Checker

Check the hole or notch you are about to cut in a wall stud against the 2021 IRC limits, and see the largest size that passes, before you pick up the drill.

Your stud
Stud size

Depths of modern dressed lumber: 2x4 = 3 1/2", 2x6 = 5 1/2", 2x8 = 7 1/4". Measure an old or rough-sawn stud and pick Other.

Wall

Every exterior wall counts as the first kind. Pick non-bearing only for an interior partition that holds up nothing but itself. If you are not sure, leave it on load-bearing.

Stud at this spot

Pick Doubled only if two full studs stand side by side here and the hole goes through both. The code does not say how a stud is doubled; ask your building department what counts in an existing wall.

What you are cutting
in
The size of the bit or hole saw, not the pipe. Inches with fractions, like 1 3/8 or 2 9/16.
Where the hole sits across the stud
Result
Not checked yetEnter your stud and the hole or notch to see the result.

    Maximums are rounded down to the 1/16 in below the exact limit, so the figure shown is never over. 2021 IRC Section R602.6.

    Side of the stud, drawn to scale across its depth. Shaded strips are the 5/8 in a hole must stay out of.

    Rule: 2021 IRC R602.6 · Tested against 24 worked examples, 6 printed in a published source · How this is worked out →

    Common cases

    Questions people ask

    How big a hole can I drill in a 2x4 stud?
    Under 2021 IRC R602.6 a hole in a single 2x4 stud in an exterior or load-bearing wall can be up to 40% of the stud depth, which is 1.4 in, so 1 3/8 in is the largest sixteenth that passes. In an interior non-bearing partition the limit is 60%, which is 2.1 in (2 1/16 in). For a 2x6 bearing stud the 40% limit is 2.2 in. The rim of the hole must also stay at least 5/8 in from the edge of the stud.
    Can I notch a load-bearing stud?
    Yes, within a limit. A stud in an exterior wall or bearing partition may be cut or notched no deeper than 25% of its depth: 7/8 in for a 2x4 and 1 3/8 in for a 2x6. In an interior non-bearing partition the limit is 40% of a single stud depth. A bored hole may not be in the same section of the stud as the notch.
    What if the pipe needs a bigger hole than 40% in a bearing wall?
    The code allows a hole over 40% and up to 60% of the stud depth in an exterior or bearing wall only where the stud is doubled, and no more than two doubled studs in a row may be bored that way. For a doubled 2x4 that is up to 2.1 in (2 1/16 in). The section does not say how an existing stud is to be doubled, so ask your building department. It also has an exception for approved stud shoes installed to the manufacturer’s instructions.
    How close to the edge of a stud can a hole be?
    The edge of the hole must be at least 5/8 in from the edge of the stud. This tool checks that on both sides of the hole, so a hole that is small enough can still fail if it is drilled too far off centre.
    Can a stud have both a hole and a notch?
    The code says a hole may not be located in the same section of the stud as a cut or notch, and its figures word that as the same cross section. Neither gives a spacing. This tool reads it as the same height on the stud: a hole level with a notch fails, and a hole above or below one passes this check. If yours are close together, ask your building department.