Ask anyone who shares a bathroom and they'll tell you the morning conflict is rarely about the second sink. It's about elbow room. "Double" gets stamped on cabinets that genuinely fit two adults and on cabinets that still force you to take turns. Before you commit to a size, run the honest math on what each width actually gives you — and whether you want two sinks at all.
The honest math on double vanity widths
An adult at a sink occupies roughly 20 to 24 inches of shoulder width, and needs a bit more to move comfortably. For two people to use a vanity at the same time without bumping, each needs about 30 inches of vanity to themselves — sink roughly centred, with a sliver of counter on either side. That rule sets the tiers:
| Vanity width | Approx. metric | Two sinks? | What it's actually like |
|---|---|---|---|
| 48" | 122 cm | Not recommended | Two sinks here leave almost no counter. Better as a generous single. |
| 60" | 152 cm | Workable minimum | Two people fit, shoulder to shoulder. Little to no shared counter between sinks. |
| 72" | 183 cm | Comfortable | Real personal space plus usable counter in the middle. The sweet spot. |
| 84"+ | 213+ cm | Generous | Room for a full makeup or grooming zone between or beside the sinks. |
The short version: 60 inches is the workable minimum for a true double; 72 is where sharing stops feeling like a compromise. If your wall can take 72, take 72.
What a 60-inch double actually costs you
At 60 inches, the sinks usually sit about 30 inches apart on centre — meeting the minimum, but leaving only a narrow strip of counter between them that fills up fast. You also pay a storage tax: two drains mean two P-traps, each eating into the cabinet below. On many 60-inch doubles, the only fully usable storage is the middle bank of drawers.
None of that makes 60 inches a bad choice. It's the right call when two people genuinely get ready at the same time and the wall won't fit more. Just know the trade: simultaneous use, at the cost of counter space and cabinet volume.
The underrated alternative: one sink, double the counter
Here's the option too many renovations skip past: a 48-to-60-inch vanity with a single sink, often offset to one end. You keep one drain, one faucet, and one rough-in, and everything else becomes counter and storage. In practice, a 60-inch single often serves a couple better than a 60-inch double — one person at the sink, the other at a long stretch of counter doing everything that doesn't need running water.
It's cheaper to plumb, easier to keep tidy, and the cabinet underneath is nearly all usable. If your mornings are staggered even by ten minutes, browse the full vanity collection with an open mind about sink count — the single-sink 60 is the quiet overachiever of the category.
Sink spacing and faucet choice
If you do go double, spacing rules keep it usable:
- Sink centres: a minimum of 30 inches apart, with 36 inches noticeably more comfortable.
- Edge clearance: keep each sink's centre at least 15 inches from side walls or tall cabinets so nobody grooms with an elbow pinned.
- Faucet format: a widespread faucet with 8-inch centres needs a deeper, wider deck behind each basin. On a tight 60-inch double, single-hole bathroom faucets keep the deck cleaner and free up a few precious inches of counter. Brands like Riobel and Kalia offer the same finish families in both formats, so you can decide by space rather than style.
Mirrors and lighting over a double
Two sinks give you a choice: one wide mirror spanning the vanity, or two centred over each basin. One large mirror makes the room feel bigger and is easier to light; two mirrors define personal zones and let you fit a sconce between them, which lights faces more evenly than a single bar above. Keep each mirror a few inches narrower than its sink zone — over a 60-inch double, that means a pair in the 22-to-26-inch range. Mirrored medicine cabinets, like those from Sidler, also return some of the storage the second sink took away. See the bathroom mirrors collection for both routes, and wall sconces for the two-mirror layout.
The plumbing bill for a second drain
This is the line item that surprises people. Converting a single-sink wall to a double means a second drain arm, a second trap, proper venting, and new supply lines. How painful that is depends on what's behind the wall:
- Easy: the existing stack is in the same wall and the new drain can tie in a few feet away, with venting that still meets code.
- Moderate: the wall is open anyway during a full renovation, so the plumber reworks drain and vent runs while everything is exposed.
- Hard: an exterior wall, a concrete condo slab, or venting that has to travel — this is where quotes climb quickly.
Get the rough-in conversation done before you order the vanity, because drain and supply positions dictate which cabinets will actually fit. The same measure-first logic applies elsewhere in the bathroom — our guide to shower base sizes and drain locations covers the shower side of the same problem. And don't forget the small parts: two basins means two pop-up assemblies from the sink drains collection, matched to your faucet finish.
Wall-mount vs floor-standing at these widths
At 60 to 72 inches, mounting style changes both the look and the install.
Wall-mount vanities make a wide cabinet feel lighter, show more floor (which visually enlarges the room), and make cleaning underneath trivial. The catch: a 72-inch floating cabinet with a stone top and two filled basins is a serious cantilevered load. It needs solid blocking in the wall, and drain plumbing positioned to hide within the shallower cabinet body.
Floor-standing vanities are the forgiving choice: they carry their own weight, offer more storage height, and conceal existing plumbing that isn't perfectly placed — the practical default for retrofits keeping the rough-in where it is. At 72 inches and up, a floor-standing piece also reads as furniture.
Neither is "better" at these widths. Wall-mount rewards planning; floor-standing rewards reality.
Frequently asked questions
Is a 60-inch double vanity big enough for two people?
Yes, but it's the minimum, not the ideal. Two adults can use it simultaneously with sinks about 30 inches apart on centre, but shared counter space between the basins is minimal. If your wall allows 72 inches, the extra foot is where a double vanity goes from workable to genuinely comfortable.
How far apart should two sinks be in a double vanity?
Plan for a minimum of 30 inches between sink centres, and 36 inches if the vanity width allows it. Also keep each sink centre at least 15 inches from side walls or adjacent tall cabinets so both users have real elbow room.
Should I choose one wide mirror or two mirrors over a double vanity?
One wide mirror makes the room feel larger and simplifies lighting; two mirrors create defined personal zones and let you place a sconce between them for more even face lighting. Size individual mirrors a few inches narrower than each sink zone — typically 22 to 26 inches each over a 60-inch double.
Is adding a second sink expensive if I only have one drain?
It can be, and the cabinet is the cheap part. A second basin needs its own drain arm, trap, venting, and supply lines. Tying into a nearby stack in the same wall is straightforward; exterior walls, concrete slabs, or vent rework push costs up quickly. Get a plumber's assessment before ordering — or consider a wide single-sink vanity, which delivers most of the benefit with none of the plumbing work.