After my son and I made his miniature Nicholson Bench, I had a fair amount of 2×12 and other 2x material left over. You could make this chair from a single 10 foot long 2×12. I wanted to keep the build simple by using only 3 power tools (as mentioned on The Dusty Life podcast) so I kept the joinery simple and used only the circular saw, cordless drill/driver, and a 6″ random orbital sander. However, those were not the ONLY tools I used. I have a tendency to over complicate things such as the joinery between the seat and the legs. I could have just used a ledger with screws to hold the seat in place but I wanted to make a dado as you will see in the video. The goal for this chair was to learn angles and how to make a comfortable chair from a combination of geometry and sizing.
If you choose to make this chair I would change one thing: cut a radius the front of the arms for your hands to rest and/or make the top of arms slope down from back to front to allow your arms to rest naturally. For me this chair was to serve a single purpose in my shop and that was to replace the old and very uncomfortable stool I sat on while recording The Dusty Life podcast.
Here are a few shots of the model I followed. For the seat, I set it sloped at about 8 degrees and put 1-1/2″ taper on the sides from front to back so the rear legs sat closer together and the chair was not as boxy. The back edge of the chair had a 3 degree bevel cut to allow the chair back to register at that angle to the seat during assembly. The side edges of the chair back had bevel cuts to match the seat taper so the arms matched the sides of the chair back as well. You can use all the parts from the chair to register your cuts accordingly. There really was no measuring once I cut the seat to shape. Everything was measured from that component.