BigBoy upcycled Fanny pack

I have this project in my head where i want to turn an old jacket into a fanny pack. But before cutting it, i wanted to check if the dimensions i was looking for were ok. This is the result with scraps. A 28*13*8cm big baby made from Dyneema and mylar. The 5cm straps is very comfortable and the Molle on the sides can be the future home of your keys or a stem bag.