The Brannock device is NOT the Holy Grail of measurements. Sure it might give you length accurately, which for me is all that it is good for, but the rest of the measurements are so inaccurate that they should, in theory, be ignored.
You see, the foot is a complex thing to try and ascertain someone’s size and a two-dimensional measurement doesn’t even come close to telling you not only what the person should be, but more importantly what they like (i.e. how the shoe should feel). I cannot argue with the length measurement as I find it pretty accurate but the width and the arch are completely off. Allow me to explain.
I measure a US8, between A/B width with an arch length of US11. I can wear a US8 narrow (UK7D) or a US7.5 medium (UK6.5E). The problem is that my foot is not really that narrow but more so shallow. And the girth of a foot is a very important measurement that is not taken into true account on the brannock. And not to mention the ridiculous arch length as I feel best in an arch of a US7.5/US8 sized shoe. And that is the problem with it and how certain salesmen will sell you on it. I have seen guys whose feet measure at a US E width but in reality need EEE for their instep or girth of foot.
Now, let’s take into account that the fitting of a shoe is really subjective, mainly based on how people like their shoes to fit. Many French people for example, like a very tight fitting shoe, might measure at a UK8 and wear UK7. Whereas Americans don’t want to feel restricted and often wear shoes too big to not ‘feel the shoe’. Who is to say which is right or wrong, but in both cases the Brannock would have given you a size the customer didn’t want.
The only accuracy to getting your size is to try the shoes or find someone that knows many brands very well and can assist you based on what you feel comfortable in already. But telling someone your brannocksize for online shoe sales will most likely end up in an incorrect fit as shoes and feet are more complex than a 2D measurement.
Don’t believe everything the salesmen at the department store tells you.