For a round bowl, start with the TOTO SS113#01 SoftClose seat. For an elongated bowl that matches its drawing and top-mount hardware, consider the SS124#01. Confirm your bowl model, shape and mounting access before buying either seat.
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This guide covers nonpowered replacement seats. It compares the TOTO documents with exact Amazon offers and keeps SS114 as a reference model because its checked offer lacked a standard cart button.
TOTO plain toilet seats compared
| Model | Shape / drawing dimensions | Mounting point to check |
|---|---|---|
| SS113#01 | Round; 16-1/2 in. long, 14 in. wide; 5-1/2 in. bolt spacing | Standard instructions show nuts below the bowl |
| SS124#01 | Elongated; 18-5/8 in. long, 14-1/16 in. wide; 5-1/2 in. bolt spacing | Top-mounted hardware included |
The dimensions come from TOTO’s SS113/SS114 sheet (totousa.com) and SS124 sheet (totousa.com). Both list polypropylene construction, a closed-front seat and lid, and the SoftClose hinge system. Shape and hardware decide which one to investigate; neither model is a universal fit for every TOTO bowl.
SS113#01: the round-bowl candidate
Choose the TOTO SS113#01 when your bowl is round and its measurements match the SS113 drawing (totousa.com). TOTO identifies #01 as Cotton. The sheet describes a solid-plastic seat and cover, a wide back, a rounded cover with integral bumpers, and color-matched hinges with nylon studs and nuts.
The standard SoftClose installation instructions (totousa.com) show plastic bolts inserted at the hinge and nuts tightened from the underside of the toilet. Check that you can reach beneath the mounting holes. A matching round outline does not solve a hardware-access problem.
Skip it for an elongated bowl, a special bowl outline, or a mounting arrangement that has not been confirmed. Do not order an aftermarket product merely because its title includes SS113. The linked offer identifies TOTO as the brand and SS113#01 as both model and part number.
On October 15, 2026, the standard new offer was sold by Buildcom through Amazon, showed stock and had an add-to-cart button. Check the selected seller, model and stock again when opening the offer.
Check TOTO SS113#01 round SoftClose seat on Amazon →
SS124#01: an elongated seat with top mounting
Choose the TOTO SS124#01 for an elongated bowl whose shape and mounting details match its spec sheet (totousa.com). Unlike the standard SS113 instructions above, the SS124 sheet expressly includes top-mounted hardware. Its installation manual (totousa.com) shows anchors, lock washers, round washers, screws and bracket covers.
TOTO’s product page (totousa.com) describes this plain SoftClose seat as specially designed for WASHLET+ toilets and carries a limited-inventory notice. Confirm that the seller can supply the exact color and hardware before relying on this model for a project. The SS124 is still a seat and lid; that description does not turn it into a bidet or add powered washing features. Use your toilet’s exact component list and the seat drawing when choosing a replacement.
Skip it if you need a round seat or are treating the WASHLET+ wording as proof that it fits any bowl. Its overall length is different from the SS114 reference drawing, so do not assume the two elongated models have identical outlines.
On October 15, 2026, the standard new Cotton White offer was sold by eFaucets through Amazon, showed limited stock and had an add-to-cart button. The title uses SS124#01; the detail fields show SS124-01 for the same model and color suffix.
Check TOTO SS124#01 elongated SoftClose seat on Amazon →
What if the old seat says SS114?
The combined TOTO sheet (totousa.com) identifies SS114 as elongated and SS113 as round. The SS114 drawing shows 18-1/2 inches in overall length, 14 inches in width and 5-1/2-inch mounting spacing. Those dimensions help identify the old seat; they are not a promise that an SS124 will replace it on every bowl.
The SS114#01 Amazon listing checked for this guide did not show a standard add-to-cart offer, so it is not a linked purchase pick. A search full of “compatible with SS114” seats does not establish an available genuine TOTO replacement. Check the brand and full part number before following a similar-looking result.
If you are replacing an SS114, compare its outline, hinge footprint and mounting arrangement with the proposed seat. Keep the old seat and fasteners until fit is confirmed. If the toilet’s model-specific parts list names a replacement seat, that is more useful evidence than the fact that two seats are both called elongated.
Measure the bowl and check the back edge
Start with the bowl shape. Round and elongated are different choices even when their mounting-hole spacing matches. Our round versus elongated guide explains that difference. Then measure the distance between the hole centers, the bowl’s widest point and the distance from the mounting line to the front of the bowl.
Compare those measurements with the seat drawing using the same endpoints. The table repeats the lengths labeled in the drawings. Check each drawing’s measurement endpoints before treating a callout as a bolt-center-to-front distance. A shipping-box dimension is also not a seat dimension. Our toilet seat size guide shows the measurements to collect.
Check the rear outline against the tank, ledge and any shaped area behind the bowl. The seat and lid must move through their full travel without hitting an obstruction. Bolt spacing alone does not describe that clearance. Photograph the old hinge position and write down the toilet’s model number before removing it.
Top mounting is a separate choice from seat shape
A skirted bowl can change how you reach the mounting hardware. TOTO’s SoftClose parts manual (totousa.com) lists THU689 under-mount hardware and THU651N top-mount hardware. It specifically notes that THU651N is included with skirted toilets, is sold separately and is not included with the seats covered by that parts list.
Do not extend that note to SS124: it has a separate sheet that explicitly includes top-mounted hardware. Read the paperwork for the exact seat being bought. Two TOTO seats may both include “mounting hardware” while supplying different mounting arrangements.
The SS124 instructions (totousa.com) warn against pushing its anchors all the way through the bowl holes, and against overtightening its screws. Follow its actual sequence and hardware stack. Reusing an old anchor because it happens to accept a screw is not a fit check. If hardware is missing or the delivered instructions differ, resolve that before installing the seat.
Match the color suffix and replacement parts
Both specification sheets identify #01 as Cotton and #11 as Colonial White. Those are separate color choices, so “white” in a retailer’s broad color field is not enough to match an existing toilet. The two offers linked here are identified as #01 Cotton White in their titles. Compare the complete model and suffix with your bowl’s color information.
For an older seat, check the exact part diagram before buying a hinge cover or hardware kit. The multi-model parts sheet (totousa.com) distinguishes several SoftClose families, and its note limits one back cover plate to SS204. A shared SoftClose name does not establish that every small part is interchangeable.
If your bowl is an unusual shape, use the maker’s specified seat rather than choosing by brand alone. Our general toilet seat guide covers other replacement choices. This comparison remains limited to the two nonpowered TOTO offers that passed the checks described here.
Frequently asked questions
Which TOTO seat fits a round bowl?
SS113 is the round model in TOTO’s combined SS113/SS114 sheet. Match the drawing and mounting arrangement to the bowl before ordering SS113#01.
Is SS124 a bidet seat?
SS124 is a nonpowered SoftClose seat and cover. TOTO describes it as specially designed for WASHLET+ toilets, but the SS124 itself does not provide bidet washing features.
Can SS124 replace SS114?
Do not assume they are identical. Both are elongated, but their drawings and mounting hardware differ. Use the toilet’s model-specific component list and compare the exact outline and mounting details.
Does every TOTO seat include top-mount hardware?
No. SS124’s sheet specifically includes top-mounted hardware. TOTO’s multi-model SoftClose parts sheet separately notes that THU651N is not included with the seats covered by that list.
Are Cotton and Colonial White the same color?
TOTO lists them separately: #01 is Cotton and #11 is Colonial White. Match the complete color suffix instead of relying on the word white in a listing.
How we chose
We read TOTO’s SS113/SS114 and SS124 specification sheets, installation manuals and SoftClose parts notes, and visually inspected both dimension drawings. We checked the two linked standard new Amazon offers on October 15, 2026 for TOTO brand, model, color, seller, stock and cart availability. We did not test comfort, hinge life or weight capacity. SS114 was excluded as a purchase pick because the checked listing had no standard cart offer. Read our selection method and about Plumbing Picks.
Primary sources
- TOTO SS113/SS114 spec sheet (totousa.com): Model shapes, polypropylene, color codes, hardware and dimension drawings.
- TOTO SS124 spec sheet (totousa.com): Elongated shape, top-mounted hardware, material, color codes and drawing.
- Standard SoftClose installation manual (totousa.com): Plastic bolts/nuts and underside fastening.
- SS124 installation manual (totousa.com): Top anchors, washer stack and installation cautions.
- SoftClose multi-model parts sheet (totousa.com): Hardware sets and model-specific parts notes.
- TOTO SS124 product page (totousa.com): Plain seat specially designed for WASHLET+ toilets; limited inventory notice.