A single-breasted overcoat cut from a boiled wool, made to your measurements.
The shape is that of the classic overcoat: single-breasted front, notch lapels, length below the knee. It is the pockets that set the tone. The flap pocket is the formal standard, found on overcoats as early as the 19th century; the patch pocket, with its franker lines, pulls the piece towards a relaxed elegance, and that is the choice made here, with a jetted breast pocket to balance it.
It is therefore an everyday coat rather than a formal one: it is worn just as readily over a suit as over a jumper and flannel trousers.
Your measurements are taken in store with a tape measure and then confirmed on a fitting garment; length and final details are settled at that appointment.