Many of us are extremely hard on Bathrobes and there is nothing that looks worse than a stained old bathrobe, my friend who owns a local resale boutique always says never look hungry like the wolf, lol. The thing is, bathrobes can be very expensive and they can get messed up very easily. When I found this Youtube Video to learn how to make my own simple terry bathrobe with no pattern I was super excited because finally I could make a few bathrobes for myself and have them on hand as I do towels and washcloths, problem solved! The materials were super easy as well.
Fold your section of terry cloth in half and mark the middle with a pin, then lay it on the floor or cutting table and fold each side inward toward the middle, then measure 7 cm in and mark with a pin.
Then cut off a section at the bottom and make that into your sleeve, cut a shallow semi circle into the main body of your robe to make arm holes.
Original source: https://diyjoy.com/diy-bathrobe-without-a-pattern/