I have finished 3 years in college last academic year (1 year multi trades, 2 years carpentry), and in the process of getting my cscs card to get on site, but looking to do my first kinda real project, in the mean time. but the dimensions are confusing me, im good at maths and equations, i just dont know how high a chair should be or how high the arm rests should be from were the seat is, or how wide or deep the seat should be, these simple questions are frying my brain. i also wanted to know what would be the best/affordable timber to use. Any help or advice would be great, and im from the uk so please mm only seeing all these videos working in inches are frying me too, since even if you convert them to mm, they still arnt stock sizes here.