You may have noticed that a toilets weight bearing limit isn't as openly advertised as it should be. In fact, you often have to dig deep into the spec lists of products to find out if they are able to support your weight. Even then, it isn't always clear. This guide will make this process simpler and less time consuming.
Before getting into specific brands and models, lets talk averages. The average floor mounted toilet will generally support up to 1000 pounds. Wall mounted toilets will naturally be less than that, supporting around 500 pounds of weight. When you consider the average American weighs around 200 pounds, this will be sufficient for the majority of people.
Standard Kohler toilets are able to support up to 1000 lbs and 500 lbs for their wall hung product ranges. This meets ASME standards. You can learn more about these limits here.
Unfortunately, having looked at various Toto toilet documentation around the web, we couldn't locate anything similar to Kohler's document above highlighting the different weight limits. However, you can assume that their floating options meet the ASME A112.19.2-2005/CSA B4 5.1-05 National Consensus Standards for Vitreous China Plumbing Fixtures (500 lbs).
Toilet seat - If you're a heavier than average person, you shouldn't just be thinking about the strength of the bowls. Getting a heavy duty seat can also be useful. The average seat can only hold around 300 pounds. This is significantly less than the bowl. This results in a lot of broken seats. However, there are some stronger options out there, built with durability in mind. Search for the Big John 1-W is a great example which is rated up to 1200 pounds. You can also find washlet seats that make cleaning up quicker and simpler than paper.
Bowl size - We recommend sticking with larger bowls instead of short depth, 24" - 25" and 26 inch ones. A bowl that extends further from the wall can support extra weight because your weight can be more evenly distributed.