Math for upgrading 4:3 to 16:9 TV

Thanks to Software Steeplechase, I now know how to figure out what size 16:9 widescreen TV I would need to preserve the viewing size of non-widescreen formatted shows on my 4:3 standard TV. Simply multiply the the size of your 4:3 TV, in my case a 32" diagonal, by 1.22, which equals
39.04". So, in upgrading to a widescreen TV, I would be looking for a 40" diagonal 16:9 screen.

4:3 diagonal TV screen size
x 1.22 or 122% larger screen size
= 16:9 required diagonal TV screen size to lose nothing during 4:3 viewing