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Bidet attachment for TOTO toilet: will it fit?

A bidet attachment for a TOTO toilet usually fits if the toilet is a standard two-piece with a visible fill valve and bolt-on seat. The trouble comes with TOTO's skirted and one-piece models, where the plumbing is hidden, and with TOTO's own Washlet seats, which use a proprietary hose. BidetKing says the usual skirted-toilet T-valve is not compatible with TOTO Washlets because of that hose, and a TOTO adapter (THP3141) or an extension hose is needed.

Not sure what yours is? Take the one-minute quiz, leave your email at the end, and we'll send the fit check before anything ships.

Two different questions behind this search

• "I own a TOTO toilet and want a cheap attachment." This is the main case. Any standard attachment can fit if the toilet's seat bolts and fill valve are normal.
• "I want a TOTO Washlet." That is a seat, not an attachment, and it has its own fit rules. See Tushy vs TOTO and Brondell vs TOTO.

Bidet attachment for a TOTO toilet: the fit table

TOTO says its seats are sized to fit most standard North American toilets: about 18.5 inches from mounting holes to the bowl front for elongated, about 16.5 for round. The same numbers tell you which bowl you have.

Step 1: check the seat is a normal bolt-on

Lift the seat's hinge covers. You should see two bolts going down through the bowl. If the seat clips on or has no visible bolts, check the maker's guide before ordering. Then measure the centre-to-centre distance; Brondell lists 5¼ to 8 inches for its own attachment, and others vary.

Step 2: find the fill valve

The water supply runs from the wall to the base of the tank. On most two-piece TOTO toilets you can see the hose and the nut. A T-adapter goes where the hose meets the tank. If the supply is hidden behind a skirt, you need a skirted-toilet T-valve with a longer reach; install a bidet on a skirted toilet shows how. If the adapter's thread does not match the valve, bidet T-valve doesn't fit lists the causes.

Step 3: the seat and the gap

TOTO bowls are generally well made, so a mounting bar on the seat bolts sits level. The same small rise at the seat's back applies as on any toilet; bidet attachment doesn't fit covers bumpers and bolt length. If your TOTO has a soft-close seat, check that the lid still closes with the bar fitted.

Why a Washlet's hose does not take a standard T-valve

BidetKing explains that a TOTO Washlet's water connection is proprietary, so the standard skirted T-valve will not match. TOTO's own adapter or an extension hose is the fix. That is a seat issue. A plain attachment uses a common 7/8 inch T and a standard hose, and it never touches a Washlet connection. If you may fit a Washlet in future, keep the T-adapter you buy simple so you can swap it.

Which attachments are worth a look on a TOTO toilet?

We have no test data on a TOTO bowl, and we will not claim any. What a sound choice needs is the same as on any toilet: a slim bar, a hose long enough for your tank, a T-adapter that matches your valve, and a maker who lists its fit range. See best bidet attachment, bidet attachment brands and non-electric bidet attachment for how to compare. Brondell and Bio Bidet both publish bolt-spacing guides, which you can check against your own TOTO.

Cost: attachment against a Washlet

Our cost guide has the sources for the attachment range, and bidet vs washlet explains what the extra money buys.

Do you need a plumber?

Not for a plain attachment on a standard TOTO. If your fill valve is hidden, the pipe is rigid or something leaks after, a plumber is reasonable. Do you need a plumber to install a bidet sets out when.

Mistakes with TOTO toilets

• Buying a skirted T-valve for a Washlet. It does not fit that hose, per BidetKing.
• Assuming every TOTO is skirted. Many are plain two-piece toilets.
• Skipping the bolt check. A seat with unusual hinges can need different washers or longer bolts.
• Not testing for leaks. Watch the T-adapter for ten minutes before you walk away.

A worked example: checking a TOTO in ten minutes

1. Lift the seat. Note whether there are two visible bolts at the back. Take a photo.
2. Measure from the bolts to the front of the bowl. 16.5 inches is round, 18.5 inches is elongated, so you know the bowl type. Write the number down.
3. Measure between the two bolt centres and write that down too.
4. Look at the base of the tank. Can you see a hose and a nut on the left or right? If yes, a standard T-adapter can go there. If the bowl's skirt hides it, take a photo of the side and check for an access panel.
5. Read the model number on the tank's inside or the bowl's rim and search it on TOTO's site to see whether it is a one-piece, a two-piece or part of a Washlet+ set.

With those five facts in hand, any seller can give you a firm yes or no in one email. That is the same method we recommend on our Kohler page, since the problem is the same on any brand.

When a TOTO is the wrong toilet for an attachment

A few TOTO setups are better served by a seat or by a plumber. A Washlet+ combination, where the toilet and seat are designed together and the water connects through the bowl, has nothing for a bar to attach to in the usual way. A wall-hung toilet has its tank in the wall, so the supply is not where a T-adapter goes. In those cases, a seat made for that toilet or a handheld sprayer with its own shut-off is the practical route. A plumber can tell you in a visit which of those your wall allows.

For everything else, a TOTO is as easy as any toilet and often easier, because the bowl and seat are made to a tight tolerance. If your toilet is not a TOTO, do bidet attachments fit all toilets gives the general checklist.

Questions TOTO owners ask before buying

Most people who search for a bidet attachment for TOTO toilet models are asking one of three things: will it fit, will it void my warranty, and will it look right. Fit is covered above. On the warranty, we do not know TOTO's terms for a toilet with a third-party part, so read your toilet's warranty page or ask TOTO before you fit anything; an attachment does not change the porcelain, but the water connection is a place a claim could be argued. On looks, an attachment is a slim bar under the seat and a short hose by the tank, and a TOTO's clean lines show it less than a rough one does.

If you want to remove it later, the process is quick; see how to remove a bidet attachment. Choosing a bidet attachment for TOTO toilet owners is mostly a matter of measuring once and buying once.

Where ASSJET fits

ASSJET is a no-plug attachment: one knob, cold water, five minutes to put on, for a standard seat and a standard fill valve. It isn't on sale yet, and we will ask for your model and measurements before you pay, so a TOTO that does not suit it gets a plain "no". The waitlist is on the quiz.

FAQ

Does a bidet attachment fit a TOTO toilet?

Usually, on a standard two-piece with exposed bolts and a normal fill valve.

Can I put a non-TOTO attachment on a TOTO?

Yes. The seat and water line are standard in most cases; check bolt spacing and the valve thread.

Will a skirted TOTO need a special part?

Often a skirted-toilet T-valve with a longer reach.

Why will my T-valve not fit a TOTO Washlet?

The Washlet's hose is proprietary; TOTO's adapter or an extension hose is the fix.

Is a Washlet worth it over an attachment?

If you want warm water and a dryer and have an outlet, many owners say yes; if you only want to rinse, an attachment does it for less.

How do I find my TOTO's bowl shape?

Measure bolts to the front of the bowl: about 16.5 inches round, 18.5 elongated.

More plain answers in our bidet guides, or find your bathroom god.

Sources

1. Installing a TOTO Washlet on a Skirted Toilet, BidetKing. https://bidetking.com/blogs/bidets/installing-a-toto-washlet-on-a-skirted-toilet
2. Bidet T-Valve for Skirted Toilets, BidetKing. https://bidetking.com/products/t-valve-for-skirted
3. Washlet, TOTO USA. https://totousa.com/washlet
4. Fit and Compatibility Requirements, Brondell. https://help.brondell.com/hc/en-us/articles/34579633981709-Fit-Measurement-Guide-Toilet-Compatibility