There is no single faucet hole size. It depends on the faucet type and model. A single-hole faucet is often quoted at 1⅜ inch (35 mm), but Insideast's own products range from a 0.90 inch (23 mm) valve hole on a bridge faucet to a 2.20 inch base on a combined single-hole design. Always measure your existing holes and check the specific faucet's own size guide before you order or drill.
Search "faucet hole size" and you will find a different number on almost every page: 1⅜ inch here, 1¼ to 1½ inch there, 32 mm on one site and 35 mm on the next. None of these pages are wrong exactly, they are each describing one faucet family, not every faucet ever made. This guide covers what the numbers actually mean, why they vary, and how to measure your own sink or countertop (worktop) before you buy.
Why "standard" faucet hole size is not one number
Several plumbing sites quote 1⅜ inch (35 mm) as the industry default for a single-hole faucet. Others give a range of 1¼ to 1½ inch (32 to 38 mm) across kitchen and bathroom faucets generally, and note that some brands use a proprietary size outside that range entirely. One detailed guide puts it plainly: even a 1/16 inch difference can affect the water seal, so a rule of thumb is a starting point, not a substitute for the manufacturer's own spec sheet.
Insideast's own products make the same point with real numbers rather than an average. Across the five faucets covered in this guide, the pre-drilled hole size on the installation guide ranges from 0.90 inch (23 mm) on a bridge faucet valve, to 1.10 inch (28 mm) on a widespread valve, to 1.20 inch on a wall-mounted valve, up to 2.20 inch on a combined cross-handle single-hole faucet. Several different products, several different holes. The sections below show each one.
External reference
"Standard faucet hole sizes (typically 1¼ to 1½ inches) provide flexibility while ensuring compatibility across most kitchen and bathroom fixtures... Always consult the manufacturer's installation manual for exact size of faucet holes in sink requirements, even 1/16 inch differences can affect water seal integrity."
For UK buyers, the same caution applies to a kitchen tap hole. Search only ever for "kitchen tap hole size", since the bare term "tap hole size" returns results for screw-tapping a metal hole rather than plumbing.
1-hole, 3-hole, and 4-hole configurations
Before diameter, count your holes. That decides which faucet style can fit at all.
| Configuration | What it is | Typical spacing |
|---|---|---|
| 1-hole (single-hole) | Spout and handle, or handles, mount through one deck opening | Not applicable, one hole only |
| 3-hole, centerset | A fixed, compact unit with spout and two handles built in | 4 in (102 mm) between the outer holes |
| 3-hole, widespread | Spout and two handles as separate pieces, connected under the deck | 8 to 16 in (203 to 406 mm) between the outer holes |
| 3-hole, bridge | Spout and handles joined above the deck by an exposed bridge | Commonly 6 to 8 in (152 to 203 mm) between the outer holes |
| 4-hole | A 3-hole configuration plus one hole for a side spray or soap dispenser | Same as the 3-hole spacing, plus one extra hole |
These spacing figures are general references from plumbing sources, not a guarantee for any specific faucet. The hole count matters as much as the diameter: switching from a single-hole faucet to a bridge or widespread style usually means drilling new holes, which our single-hole faucet compatibility guide covers in more detail, including how to cover any extra holes left behind.
Kitchen faucet hole sizes, with real spec sheets
Here is what two current Insideast kitchen faucets actually require, taken from their own installation guides rather than a general estimate.
Bridge kitchen faucet
Heritage: 0.90 in recommended hole
The Heritage bridge faucet uses a 3-hole configuration, drilled 6 in (152 mm) on center, with 3 in (76 mm) from each outer hole to the center. Its own installation guide recommends a 0.90 in (23 mm) hole for each valve.
Browse the bridge kitchen faucets or view this faucet.
Wall-mounted kitchen faucet
Wall-mounted bridge: a different shape and installation
This wall-mounted bridge faucet is a useful example of a different faucet shape and installation method: it mounts through the wall rather than the deck, using its own rough-in valve rather than a countertop hole. Its installation guide gives the rough-in spacing and depth needed before the wall is finished.
For more kitchen faucet styles and how to choose between them, see our Heritage, bridge, and gooseneck styles guide, or the wider unlacquered brass faucets buyer's guide.
Bathroom faucet hole sizes, with real spec sheets
Bathroom faucets vary even more, since a single-hole design can be a simple lever or a full cross-handle unit that needs a much larger opening. Here are three current Insideast bathroom faucets, again from their own installation guides.
Single-hole bathroom faucet
2.20 in base, larger than a typical single hole
This faucet combines both handles and the spout into one body, so its single hole is wider than the 1⅜ in figure often quoted for single-lever designs. Its own guide gives a 2.20 in (56 mm) base diameter, 5.60 in overall width, and 5.20 in height.
Widespread bathroom faucet
1.10 in valve, 0.90 in spout, 8 to 10 in spread
This 3-hole deck-mount faucet needs two different hole sizes on the same countertop: 1.10 in (28 mm) for each valve body, and a smaller 0.90 in (23 mm) hole for the spout. The guide recommends 8 to 10 in (203 to 254 mm) between the two outer valve holes.
Wall-mounted bathroom faucet
1.20 in hole, G½ female thread, 8 in spacing
This wall-mounted vessel and basin faucet needs a 1.20 in pre-drilled hole for each valve, threaded G½ female, spaced 8.00 in apart with 2.60 in from each valve to the spout. Mounting depth runs from 2.60 in minimum to 3.30 in maximum behind the finished wall.
The faucets featured here ship with their own installation and size guide, and any of these dimensions can be customized on request. If your sink or countertop (worktop) does not match the numbers above, email contact@insideast.com with your measurements before ordering, and the team will confirm fit or offer a custom size. For a full walkthrough of swapping one bathroom faucet for another, see how to replace a bathroom faucet.
Measuring your countertop or sink
- Count the existing holes in your sink deck or countertop (worktop)
- Measure each hole's diameter with a tape measure or calipers
- If there is more than one hole, measure center to center between them
- Measure the thickness of the deck or countertop, since thick stone may need an extension tube
- Note the thread type your plumbing uses, NPT in the US or BSP in the UK and Europe
- Compare your numbers against the specific faucet's own size guide, not a general average
If you are ordering a new sink alongside a new faucet, this step is easier: the holes can be drilled to match the faucet exactly, so confirm the configuration with your supplier before the sink is cut. Our guide on how to choose a kitchen sink covers matching a sink to its faucet in more detail.
What if the hole is the wrong size?
Whichever situation applies, the safest first step is the same: email contact@insideast.com with your hole count, diameters, and spacing, and the team will confirm fit, a deck plate, or a custom size before you order or start cutting.
Frequently Asked Questions
What is the standard faucet hole size?
Are all faucet holes the same size?
What is the difference between a 1-hole, 3-hole, and 4-hole faucet?
How do I measure my sink or countertop for a new faucet?
What if my faucet hole is the wrong size?
Any of the dimensions shown here can be customized on request. Browse the kitchen faucets or bathroom faucets, or email contact@insideast.com with your measurements and we will confirm fit before you order.
