So you’d like to replace your old outdated toilet with new water saving low flow model?
Great! So what size toilet will you need for the replacement toilet installation?
When I ask that question, the reaction is usually a blank stare followed by “what do you mean what size?” Well, all toilets, whether one-piece or two-piece (tank and bowl combination), come in three sizes. Those sizes are 10″, 12″ & 14″ with the 12″ size being the industry standard and the go-to size I use in a new renovation setting.
What determines which size to use?
Well when replacing an existing fixture, the determining factor is always the distance from the finished wall where the tank will sit, to the center line of the closet bend – lead bend or waste bend (all the same just different names). Now, this measurement can vary greatly from as little as 9 1/2″ to as much as 14″ or anywhere in between.
In general, the rule would be if your wall to center measurement is 10″/12″/14″ you would use the corresponding sized toilet. This is exactly what I do when replacing an existing fixture, but when I’m setting a new closet bend, my experience has taught me to set that distance a 1/2″ less than the size toilet I plan on using. This allows the toilet sit a little closer to the back wall where the tank will rest making a much nicer and cleaner job in my opinion.
I’ve found that if I set my closet bend at 12″ followed by a 12″ sized toilet, it sits a little farther from the rear wall than I’m comfortable with.
Be careful though, any measurement beyond 1/2″ will set the toilet tank flush against the rear wall preventing the tank cover from fitting properly.
I invite you to check out my video titled “How to determine what size toilet to buy,” and if you still have questions please drop me a line at info@bobsplumbingvideos.com.
Happy Plumbing!