This oven has not been out that long but it has a fairly typical sized second oven; 2,5 cubit feet.

Usually about 13.5" wide, 18.5" deep and 18.5" high.

Normally, you can fit half commercial bakers sheets.

If not then a slightly smaller jelly roll pan.

I use a half commercial bakers sheet for everyday cooking for 3. I guess if you have a really large family it might get very little use but I use my small 24" wall oven with the half sheet almost every day and my 36" range oven a couple of times a month. Usually when guest are coming over.

Hopefully someone who owns this range can measure the rack and let you know the usable space and more importantly how it actually bakes. In the past there have been discussions that some brands of 48 inch ranges did not accommodate even 9x13 inch pans well in the small side. They might technically fit but do not heat evenly. You need to leave some space on the sides for air circulation. Some 48 inch ranges have convection fans in both ovens to help with this.