If you have ever agonised about buying shoes online, let me save you some inconvenience.
After deliberating which size you are, but before you hit purchase, email the website and see if they can provide you with a measurement for the insole of the sizes in question.
Using an accurate insole measurement is the only way to make sure that a pair of shoes will absolutely fit.
I have tried several times to buy shoes online. The results were usually pretty disastrous, until I learned this simple trick. Would you believe that my foot is 22cm, but I wear a 24cm insole? I wouldn’t have thought this was right, but it turns out your feet need that much wriggle room.