they are like sweatpants at the waist. so the number is pretty meaningless. how long do you need them to be? polar has charts for everything. i'd say refer to the chart for your personal size.
i fit 30 at the waist but i like to wear 31 or 32 for added comfort in whatever pants. 30 with the leglength. i wear a small in surf pants, fits great. slightly stacking on my shoes. no idea if i have the short or tall version, i bought mine before that was a thing. again, i'd refer to their chart.