Flip the base upright, put the MDF on top of it, then use a straightedge to draw two straight lines joining the outside edges of the legs and extending the width of the MDF. I used the countertop as the straightedge. We cut it with our cutting guide, which is based on the factory edge of a sheet of 1/4" plywood, so it should be straight enough. Use a carpenter's square to transfer these lines onto the ends of the MDF.
Stop it. Really. I mean it. Pick a height between your thigh and waist that seems right. You’ll adapt. Don’t worry about your back. You’ll adapt. If you are really uncertain, make it a little taller and then cut down the legs. After a decade or so, your work habits will put a magic number in your head. You’ll have built enough furniture that you will know your number. Until then, pick a number.
This table top is also made from the hardest wood out of any manufacturer we reviewed: oak. In fairness, this can be both a blessing and a curse. The oak wood is extremely durable and noted for its lack of a porous nature. This means the top can withstand plenty of abuse from tool and workpieces. Moreover, you will not have to worry about liquids like lacquers and stains from being absorbed into the top. That said, the hard oak can also do a number on tool sharpness, dulling them prematurely if they are not carefully handled.