Quote Originally Posted by jadnashua View Post
But, it still comes back to my main point...you can't size the WH until you know what you expect out of it. Someone that takes 'military' showers - maybe a minute or so in length could easily get by with a much smaller tank than someone who likes to turn into a prune before getting out.
We take 7-10 min showers typically and have very cold water in mid-winter--below 40 F. We can run all three showers simultaneously and run washing machine or dishwasher without problems. Of course we have a front loading washer, an energy star dishwasher, and 1.5-1.6 gpm showerheads. We've not ever run out of hot water except for the whirlpool tub, even when 3 more adults were staying with our family of four. This was true even at 125 F set point in mid-winter for 50 gallon tank with company staying.

However, I note the dual showerheads listed by the original poster for the master bath. And I assume all of their showerheads will be in the 2.2-2.5 gpm range. Then add in the slow recovery rate of electric vs. what we have for gas. So it seems best to go for some overkill in the infrastructure, even if a 2nd tank is never installed.