These are the fourth pair of Docs I've owned, but my first pair of steel toe, and man, is there a big difference.

For reference, my go-to shoes are&nbsp;<a data-hook="product-link-linked" class="a-link-normal" href="/Dr-Martens-Men-s-Zack-Slip-On/dp/B000EU148S/ref=cm_cr_arp_d_rvw_txt?ie=UTF8">Dr. Martens Men's Zack Slip-On</a>, and like the Docs before them, UK 12 / US 13 has been a perfect fit on me. However, these Resistors run incredibly tight. 12/13 wouldn't even go on my bare foot, let alone with socks. The tight fit is top to bottom, rather than length or width, and I have really flat feet -- so I can't imagine how anyone with even the slightest arch would fit in to these if they were a US 13.

Undeterred, I exchanged them for 13 / 14, and those fit, but again, really, REALLY tightly. If Amazon carried 14/15, I probably would have skipped straight to those.

Since I don't have a practical use for steel toe shoe, I'm on the fence right now about sending them back and going with some black Zacks to go with my brown ones, because like every other pair of Docs I've owned (or even tried on), those are incredibly comfortable.