I'm seriously considering this dress, but is very unsure about the sizing. My body type varies between apple/hourglass and hourglass/apple, dependent on weight (these days 60kg / 132 Ib 4oz). Usually I'm between S and M or European/German size 36-38.

My height is: 157 cm / 5'2"
From neck/shoulders to waist (narrowest part): 38-9 cm / 15"
Bust: 88 cm / 34"6
Waist (narrowest): 81 cm / 31"9
Tummy (widest): 94 / 37"
Hips (widest) 92 cm / 36"2

I guess petite size S or M would be the right depending on the sizing of this dress.

ETA: hopefully I've done the conversion right. Math was never my best subject