My actual waist measurement just below my belly button is 37 inch, my hips are 36 inch. I wear 36 inch trousers as I dont wear them high up around my waist. I can fit into some 34 inch shorts though but they are kinda tight and the elastic is stretched all the way lol.
I can squeeze into 34" shorts too, and 36'ers often require a belt depending on the cut...yet if I tape my hips or waist, the reading is 40".