Inner tubes come in 3 different valve lengths.

What we used to call "standard" tubes have 36mm valves. They work best with box section rims. A lot of bike shops have stopped stocking them in order to minimize the number of inventory skews. I stopped buying inner tubes locally simply because 36mm tubes are hard to find in stock.

The new bike shop "standard" are 48mm tubes. That's about 2" long. If your wheels have profile depths of 25 or 30mm, these are what you are probably looking for.

There are also 60mm tubes. They work best only if you have very deep section wheels. They look really dorky if you have box section rims like me.