Bio Bidet Toilet Seat Compatibility Guide

Interested in purchasing a bidet seat or bidet attachment, but not sure if it’s compatible with your toilet? This Bio Bidet toilet compatibility guide will walk you through how to measure your toilet for a bidet seat or attachment to make sure you order one that will fit.

Our bidet seats and attachments fit on most modern toilets; however, they may not be compatible with some older or specialty models.

Most of our bidet seats, like our Slim Two bidet seat, come in either elongated or rounded models to fit almost any toilet. Our bidet attachments fit under both elongated and rounded toilet seats.

There are two main types of toilet bowls: elongated and round. Older and more basic toilets are round, while more modern, deluxe toilets have an elongated bowl.

Elongated toilets are more oval-shaped than round, as shown in the diagram below. If you're uncertain about which type you have – here’s how to measure your toilet for a bidet seat or attachment:

  • To measure the length of the bowl, locate the two mounting bolts at the seat hinge. From there, measure to the very front of the toilet bowl in a straight line. That straight line measurement will be about 16-1/2 inches if the bowl is round, and 18-1/12 inches if your bowl is elongated.
  • You'll also need to measure the distance between the toilet bolt holes.  Any distance shorter than 5.5 inches or greater than 7.5 inches will likely be incompatible.


 16.5 Round, 18.5 Elongated

Difference Between One-piece and Two-piece Toilets

In addition to elongated and round toilets, there are also one-piece and two-piece toilets to be aware of. Here are the descriptions of the two types of toilets:

  • one-piece toilet is sculpted into a seamless unit and has no crevices between the tank and bowl.
  • A two-piece toilet is one that has a separate tank and bowl that are bolted together upon installation.

Bio Bidet products are designed to fit almost all one-piece and two-piece toilets. However, there are some exceptions such as category "C" below. Bio Bidet seats and attachments don’t fit well on category “C” toilets as the design and shape of these have limited space near the mounting bolts.

If you have a one-piece toilet with a deep French curve, please contact us with the make and model of your toilet for a compatibility check.

Will a Bidet Seat or Bidet Attachment Fit My Toilet?

If you’re still unsure if our bidets will fit your toilet, use the chat feature on our website to speak with a customer service representative or send us a message on social media. We’re on Facebook, Instagram, and Twitter.

Need to know how to install a bidet?

More Toilet Compatibility Resources

Click here to download a print-to-size compatibility template for the Discovery DLS bidet seat.

The following information is a general guide at compatibility with Bio Bidet models and some popular options from toilet manufacturers.

American Standard

Good Models Antiquity, Astute Vormax, Boulevard*, Cadet1-4, Clean, Colony, Edgemere, Mainstream, Portsmouth, Reliant, Repertoire, Retrospect, Saver, Studio Dual, Titan, Town Square*, Tropic, Yorkville
Bad Models Fairfield&, Tofino*



Good Models Belmont, Belmont HET*, Diplomat, Diplomat Compact, Stratus
Bad Models Canterbury


Glacier Bay

Good Models N2316, N2410EB/2410T , N2424EB/N2424T,  N2430
Bad Models N2420*



Good Models Adair*, Archer*, Bancroft, , Barrington, Cimarron, Devonshire, Highline, Kathryn*, Kelston, Memoirs*, Portrait*, Saile*, Tresham, Wellworth
Bad Models Gabrielle*, Persuade, Reve*, Rialto, San Raphael*, Santa Rosa*, San Souci*



Good Models Alto, Barrett, Brentwood, Cascade, Denali, Maverick, Mont Clair, Pro-Fit 1-4, Protector, Quantum, Summit, Waverly
Bad Models Aegean



Good Models

Aimes*, Carolina*, Carlyle, Clayton, Dartmouth, Drake, Drake 2, Entrada, Guinevere*, Legato*, Lloyd, Nexus, Promenade, Rowan, Soiree*, Supreme*, Supreme II*, Ultramax*, Ultramax II*, Vespin II

Bad Models Aquia, Whitney



Good Models

Brevard, Corrente, Foundations, Lilah, Prelude, Riosa, Turner

Bad Models Luxford


Good Models Hinsdale and Avalanche


Models with a * next to their names are 1 piece toilets. 1 piece toilets should be viewed with extra scrutiny as the width of the unit where the tank connects to the bowl could be too wide for our non-electric bidets to fit since some of their components hang down to the left or right side of the toilet. These non-electric units are the BB-70, BB-270, Elite3, A3 and BB-i3000.

However, these 1 piece toilets should pose no issue with our electric units as they fully sit on top of the toilet rim. These electric units are the DIB, A7, Slim1, Slim2, USPA U, BB-600, BB-800, BB-1000, BB-1700, BB-2000, DIB, A8, USPA4800 and USPA6800.