We all know sizing through the vast amounts of different brands and lasts is difficult.
To help guide a little, we have made a size chart of what our staff wears in the different lasts.
Your experience may differ from ours, so don't hesitate to contact us for further help.

Stefan

Maker and last

Size and Width

Comment

 Alden - Barrie

10.5 E & 11 E

10.5 fits close to the foot, while 11 is a little more loose and comfortable. I prefer 11 for boots.

 Alden - Van

 10.5 E and 11 D

Both work well. 11 D gives a little extra space in the toe box that I prefer for loafers.

 Alden - Aberdeen

11 EE

E is too slim for me.

Alfred Sargent - 87 F and 104 10.5 F Alfred Sargents standard width is F, and 10.5 fits me great.
Carmina - Rain 10.5 EE Fits snug, but with enough space. Feels similar to Enzo Bonafé 946.
Dagestad & Co - 1503 last 10.5 Close on the foot.

 Edward Green - 202, 82, 606

 10.5 F & 11 E

 11 is my preferred size. Fits snug but no pressure points.

Enzo Bonafé - 946 946 F 10.5 F fits good. Snug, and just enough space in toe box. I have quite high instep, and luckily, Enzo Bonafè does too. With low instep, I believe Enzo Bonafè to be a difficult fit.

 Foster & Son - 05

11 E

11 E fits great. Close to the foot but with no bad pressure. 10.5 F would probably be good too.

Gaziano & Girling - MH71, GG06 10.5 F 10.5 E is too tight, but F works great. 
Heschung - Odéon 10.5 10.5 looks a little long, but definitely my size. Very comfortable. Felt tight on the foot at first, but adapted nicely to the foot just in one day of wear.
Loake - Capital 10.5 F A decent fit. Feels more generous than the other formal lasts I've used.
Miyagi Kogyo 11 I need 11 in Miyagi Kogyo. 10.5 feels good in the beginning, but a little too slim in the toe box.
Paraboot - Avignon 11 I have owned this pair in 10, but when I was getting my second pair, I chose 11 over 10 and 10.5. Needed the space in toe box. 11 fits close around the foot, and with space for the toes. A very good fit for me.
Paraboot - Michael 11.5/45.5 The Michael is a difficult fit. It feels shorter than all other shoes, so I've found I need 11.5 or 45.5. 
Red Wing 11.5 US 11.5 US fits me good. 11 in E2 works too.
Skomaker Dagestad by Santari 10.5 and 11 Both sizes work. 10.5 feels really nice, and gives good support all around. Maybe my favourite last in terms of fit and aesthetics.