Hi Krish,
I used the size guide on ASOS to determine my size in these booties. I always find the footer length to be very helpful (on the Bertie booties item page, next to the "Select size" scroll down menu). Depending on brand, I wear either a 38, 38.5 or sometimes a 39, so it can get a little confusing. My feet measure 24.4 cm (= 244 mm /9.6"), so according to the size chart I was closest to a size 39 in these.
I think the booties fit quite true to size, but because I got the 39 (and that size usually is on the big side for me), they feel quite roomy. Which I don't mind, since the toe is pointy it's nice to have a bit more room in the front + I like to pop in an insole too. FYI: I'm wearing them with thin socks.
The sole is not very flexible, which often worries me a bit in a shoe, because it can indicate they are not very comfy (at least on my feet), but that's not the case here. They felt very nice and not "hard" from the get-go. There is a little bit of padding from the middle of the shoe right up to the edge of the heel. After adding an insole they feel great.
I hope this helps?
