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Quick answer from a licensed plumber: Choose by the installed footprint first. The Swiss Madison SM-1T257 has a 24-inch-deep round body; the Gerber Viper Force GRS48350 gives an elongated seat at chair height in a 27-3/4-inch-deep body. Both linked models need a 12-inch rough-in.
Start with the shortest body: Check the Swiss Madison SM-1T257 on Amazon
A short toilet can free a door or walkway, but a depth number alone does not prove it fits. Match the rough-in, read the installation drawing and check the seat before ordering. These two picks cover different needs: the shortest round body and an elongated seat at chair height.
Compact Toilets Compared by Depth
| Model | Body size: depth × width × height | Bowl and height | Rough-in | Flush | Included seat |
|---|---|---|---|---|---|
| Swiss Madison SM-1T257 | 24 × 14 × 29 in | Round; standard height | 12 in | 1.1 / 1.6 gpf | Yes |
| Gerber Viper Force GRS48350 | 27-3/4 × 16-1/2 × 31-5/8 in | Compact elongated; ErgoHeight | 12 in | 1.28 gpf | Yes |
Dimensions are from each manufacturer’s model-specific spec sheet and agree with the linked Amazon listing. Both listings showed new units in stock, shipped and sold by Amazon, on September 27, 2026. Availability can change.
Swiss Madison Sublime II SM-1T257
One-piece · round bowl · 24 in deep x 14 in wide x 29 in tall (spec sheet) · 12-inch rough-in · dual flush 1.1 / 1.6 gpf · standard height (15–17 in) · soft-close, quick-release seat included
When every inch counts, this is the one to measure first. Swiss Madison’s spec sheet lists it at 24 inches deep, 14 inches wide and 29 inches tall, which makes it the shortest toilet on this page by nearly four inches. It is a one-piece round-bowl toilet with a skirted, fully glazed trapway and a dual flush of 1.1 or 1.6 gallons.
The linked SM-1T257 is the 12-inch rough-in model, not the separate 10-inch variant. Its included seat closes softly and releases for cleaning. Compare the seat dimensions and shape with a toilet you find comfortable: a smaller exterior also means less room at the bowl.
- 24 inches deep, the shortest here (spec sheet)
- One-piece with a skirted, fully glazed trapway
- Soft-close, quick-release seat included
- Round seat may feel cramped; compact floor space does not guarantee comfortable seating
- Full flush uses 1.6 gpf versus the Gerber’s 1.28 gpf
- Standard height rather than chair height
Verdict: The pick for the tightest powder room, where a round bowl is acceptable and depth is the constraint.
Gerber Viper Force GRS48350
Two-piece · compact elongated · 27-3/4 in deep x 16-1/2 in wide x 31-5/8 in tall (spec sheet) · 12-inch rough-in · 1.28 gpf · 3-inch flush valve, Fluidmaster 400A fill valve · ErgoHeight (ADA) · seat and wax ring included
If you want an elongated seat without a full elongated footprint, this is the compact elongated to look at. Gerber says the bowl is designed for comfort while optimized for smaller spaces, and its spec sheet gives 27-3/4 inches deep, 16-1/2 inches wide and 31-5/8 inches tall. It flushes 1.28 gallons through a 3-inch flush valve, with a Fluidmaster 400A fill valve, and the spec sheet lists a MaP rating of 1,000 grams.
The included soft-close seat, wax ring and installation hardware reduce the separate parts to buy; the supply line is not included. Its ErgoHeight bowl is labeled ADA compliant on the spec sheet. That label describes the fixture: the surrounding room still needs the required clearances and layout.
- Elongated seat in a 27-3/4-inch-deep body
- 3-inch flush valve and Fluidmaster 400A fill valve
- Seat, wax ring and installation hardware included
- 3-3/4 inches deeper than the Swiss Madison
- Supply line sold separately
- Two pieces add a tank-to-bowl joint to clean and maintain
Verdict: The pick when you want elongated comfort and chair height in a bathroom that cannot take a full elongated bowl.
I send an occasional note when a new guide goes up — repairs worth doing yourself, and the parts that actually last. No spam, no course funnel; written by a licensed Georgia plumber.
Measure the Installed Position, Not Just the Toilet
- Rough-in: measure from the finished wall, excluding baseboard, to the drain center. The floor bolts usually mark that center. See toilet rough-in sizes if it is not 12 inches.
- Front clearance: use the maker’s dimension drawing to locate the bowl front relative to your drain and finished wall. Do not simply subtract body depth from the room length: the installed rear gap and actual rough-in can change the projection.
- Door and side space: mark the installed outline on the floor, swing both the room door and shower door, and check access beside the bowl. A toilet that clears the door can still leave too little usable space.
- Seat and service access: check the seat shape, usable opening and replacement-seat availability. Leave access to the shutoff, fixing points and tank lid; a skirted body can make an awkward supply location harder to reach.
Our round versus elongated guide covers shape and clearance considerations. If a full-size toilet fits after all, our best toilet picks give each top pick’s depth from the wall. Have the installer confirm the required local clearances before you commit to a tight layout. Chair height and standard height have different comfort tradeoffs; see seat-height choices.
One-Piece or Two-Piece?
The Swiss Madison has no tank-to-bowl seam, while the Gerber separates into two pieces for carrying. Neither construction guarantees a shorter toilet; the model dimensions decide. See one-piece versus two-piece toilets and what a replacement involves.
Why the Shortlist Stops at Two
We left the Kohler Highline K-5481-RA out of this depth ranking because its Amazon listing and the manufacturer information gave conflicting depth figures. A difference of two inches matters in a tight room. It needs a confirmed model drawing before we can recommend it for a strict clearance limit.
FAQ
What is the smallest toilet for a small bathroom?
Of these two verified picks, the Swiss Madison Sublime II SM-1T257 has the shortest body at 24 inches. The Gerber Viper Force GRS48350 is 27-3/4 inches deep. These are product dimensions, not a promise of the final distance from your finished wall.
Does compact elongated mean shorter than a round toilet?
Not necessarily. Bowl shape describes the seating area, while overall depth includes the tank and body. Compare the exact model’s drawing and your rough-in instead of choosing by the word round or elongated.
Can a compact toilet be chair height?
Yes. The Gerber Viper Force combines a compact elongated bowl with ErgoHeight seating. The Swiss Madison is standard height. Check actual seat height and comfort as well as the floor footprint.
What rough-in do these toilets need?
Both linked models use a 12-inch rough-in, measured from the finished wall to the floor-drain center. Swiss Madison sells a separate 10-inch variant; the Amazon link here is for SM-1T257 with a 12-inch rough-in.
Why Trust Plumbing Picks
Plumbing Picks is written by a licensed Georgia journeyman plumber. Every size, rating, dimension and spec on this page comes from the manufacturer pages and documents listed below, which we opened and read, or from the Amazon listing we link; nothing here comes from hands-on testing. Each linked product was shipped or sold by Amazon, new and in stock, when we checked on September 27, 2026. Where a link goes to Amazon we may earn a commission at no extra cost to you. Nobody pays to be included here. More on who writes this and how we pick.
Sources
- Swiss Madison: Sublime II SM-1T257 compact one-piece round
- Swiss Madison: SM-1T257 spec sheet
- Gerber: Viper Force GRS48350 compact elongated (product page)
- Gerber: GRS48350 spec sheet
Which One Fits Your Room?
Choose the Swiss Madison when depth is the tightest constraint and its round seat suits you. Choose the Gerber when an elongated seat and chair height matter and the installed footprint fits. Check the drawing against the room before buying.