What size hole saw for 4" PVC?
4" PVC measures 4.500" across. A 4-1/2" saw matches it exactly, with zero clearance.
Here's the saw for passing 4" PVC or ABS through a wall, floor or roof deck, plus the size for clearing a coupling.
Nominal size
Change the size to compare. Under each, the pipe’s real outside diameter.
Hole saw for 4-inch PVC or ABS pipe, by job
About 1/16" around the pipe, for movement and an imperfect cut.
Exactly the pipe’s 4.500" outside diameter: it can bind, and pipe at the top of its tolerance won’t go through.
When the Sch 40 coupling has to pass through the hole, not just the pipe.
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Nominal isn’t actual
Schedule 40, Schedule 80 and PVC or ABS drain pipe all share the 4.500" outside diameter. At 4.5" across, a 4" pipe is wider than the code allows for a hole in a 2x4 or 2x6 stud, so plan the route first.
Same trap as wood: lumber sizes, nominal vs actual.
Which one to use
Easy clearance leaves room for the pipe to move and for a slightly off-line cut. The exact fit is the smallest saw at least the pipe’s size; here it’s the same size as the pipe, so it can bind, and pipe at the top of its size tolerance won’t go through. In studs and joists, the code limits the hole by the lumber’s real depth: how big a hole you can drill in a stud.
Common questions
What size hole saw for 4 inch PVC?
4" PVC is 4.500" across, so use a 4-5/8" hole saw for easy clearance, or 4-1/2" for an exact fit (zero clearance: it can bind, or not pass pipe at the top of its tolerance).
Why can't I use a 4 inch hole saw for 4 inch PVC?
Because the 4" is a nominal size, not a measurement. The pipe's real outside diameter is 4.500", bigger than a 4" hole.
What size hole saw to fit a 4 inch PVC coupling through?
A 4" Schedule 40 coupling hub is about 5-1/32" across (±1/16"), so use a 5-1/2" hole saw if the coupling has to pass through.
Is 4 inch Schedule 80 PVC a different size from Schedule 40?
Not on the outside. Schedule 40, Schedule 80 and drain (DWV) pipe all measure 4.500" across at 4"; Schedule 80 just has a thicker wall. The hole saw is the same.
Full hole saw chart
Hole saw size chart for pipe and conduit
| PVC / ABS | Actual OD | Easy clearance | Exact fit | Clear a coupling |
|---|---|---|---|---|
| 1/2" | 0.840"21.3 mm | 1"25.4 mm | 7/8"22.2 mm | 1-5/16"hub 1-3/32" |
| 3/4" | 1.050"26.7 mm | 1-3/16"30.2 mm | 1-1/16"27 mm | 1-7/16"hub 1-5/16" |
| 1" | 1.315"33.4 mm | 1-1/2"38.1 mm | 1-3/8"34.9 mm | 1-3/4"hub 1-5/8" |
| 1-1/4" | 1.660"42.2 mm | 1-13/16"46 mm | 1-11/16"42.9 mm | 2-1/8"hub 1-31/32" |
| 1-1/2" | 1.900"48.3 mm | 2-1/16"52.4 mm | 1-15/16"49.2 mm | 2-3/8"hub 2-7/32" |
| 2" | 2.375"60.3 mm | 2-1/2"63.5 mm | 2-3/8"zero clearance | 2-7/8"hub 2-3/4" |
| 2-1/2" | 2.875"73 mm | 3"76.2 mm | 2-7/8"zero clearance | 3-1/2"hub 3-11/32" |
| 3" | 3.500"88.9 mm | 3-5/8"92.1 mm | 3-1/2"zero clearance | 4-1/8"hub 4" |
| 4" | 4.500"114.3 mm | 4-5/8"117.5 mm | 4-1/2"zero clearance | 5-1/2"hub 5-1/32" |
| Copper / PEX | Actual OD | Easy clearance | Exact fit |
|---|---|---|---|
| 3/8" | 0.500"12.7 mm | 5/8"15.9 mm | 9/16"14.3 mm |
| 1/2" | 0.625"15.9 mm | 3/4"19 mm | 5/8"zero clearance |
| 3/4" | 0.875"22.2 mm | 1"25.4 mm | 7/8"zero clearance |
| 1" | 1.125"28.6 mm | 1-5/16"33.3 mm | 1-1/8"zero clearance |
| 1-1/4" | 1.375"34.9 mm | 1-1/2"38.1 mm | 1-3/8"zero clearance |
| 1-1/2" | 1.625"41.3 mm | 1-3/4"44.4 mm | 1-5/8"zero clearance |
| 2" | 2.125"54 mm | 2-1/4"57.2 mm | 2-1/8"zero clearance |
| Conduit | Into a box | Through, PVC / rigid | Through, EMT |
|---|---|---|---|
| 1/2" | 7/8"NEMA 0.875" | 1"exact 7/8" | 7/8"exact 3/4" |
| 3/4" | 1-1/8"NEMA 1.109" | 1-3/16"exact 1-1/16" | 1-1/16"exact 15/16" |
| 1" | 1-3/8"NEMA 1.375" | 1-1/2"exact 1-3/8" | 1-5/16"exact 1-3/16" |
| 1-1/4" | 1-3/4"NEMA 1.734" | 1-13/16"exact 1-11/16" | 1-11/16"exact 1-9/16" |
| 1-1/2" | 2"NEMA 1.984" | 2-1/16"exact 1-15/16" | 1-7/8"exact 1-3/4" |
| 2" | 2-1/2"NEMA 2.469" | 2-1/2"exact 2-3/8" | 2-3/8"exact 2-1/4" |
| 2-1/2" | 3"NEMA 2.969" | 3"exact 2-7/8" | n/a |
| 3" | 3-5/8"NEMA 3.594" | 3-5/8"exact 3-1/2" | n/a |
| 4" | 4-5/8"NEMA 4.641" | 4-5/8"exact 4-1/2" | n/a |
Easy clearance = smallest saw at least 1/8" over the pipe’s outside diameter (about 1/16" around it), the default. Exact fit = smallest saw at least the pipe’s outside diameter; “zero clearance” means the saw equals the pipe’s nominal outside diameter: it can bind, and pipe at the top of its tolerance won’t pass. Clear a coupling = the Sch 40 coupling hub plus 1/8". Into a box, conduit follows the NEMA knockout for the trade size, the same for EMT, PVC and rigid.
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Where these numbers come from
Outside diameters are copied from the makers’ and standards’ published tables. The hole saw sizes are not typed in: they’re worked out from those diameters and the sizes saw makers actually sell, then checked at build time so a recommended hole can never be smaller than what has to pass through it. Easy clearance is the smallest saw at least 1/8" bigger than the pipe; exact fit is the smallest saw at least the pipe’s size. Millimetres are converted from inches, not copied.
- JM Eagle, Solvent Weld Schedule Series submittal (PVC Sch 40/80, ASTM D1785/D2665)
- Charlotte Pipe, PVC DWV submittal
- Charlotte Pipe, ABS submittal
- Spears, Schedule 40 PVC coupling technical sheets (fig. 429)
- Lenox, Hole Saws & Accessories catalog (sizes sold; pipe-entrance table)
- Starrett, Saws & Hand Tools catalogue (bi-metal sizes)
General sizing guidance from published pipe, conduit and hole saw dimensions. Before boring framing, check the hole limits in your local building code; for electrical work, follow your local electrical code and the fitting maker's instructions.