My removable shop shelf is for my sliding miter saw so it was designed for that weight in mind.
I wanted as much space below the shelf as possible since I was originally storing my snow blower under there so I made the supports above the shelf instead of below.
Here is a nice little formula to help figure out the dimensions you will need to support the weight you would expect.
For my shop shelf the formula came out as 44 = ( (75 × 28) ÷ 16 ) ÷ 3
75 lbs is about the weight of the saw + an average 2x6 + some of the shelf weight
28" = distance from the wall to the bed of the saw
16" = just enough clearance so the saws sliding bars would fit under the top 2x4 support
3 hooks = The shelf needed to be wide enough to allow those long sliding bars to swing left and right so it put me over 3 studs.
The hooks I'm using can support 150 lbs each but they only need to support 44 lbs, so I have a lot of extra capacity.
If you arrived to this page from somewhere else, you can click HERE to view the YouTube video