These boots run true to size. I normally wear US 10.5D boots, and the 10.5D 961s fit me quite well.

These will fit someone who normally wears 13EE boots, and possibly someone who normally wears 13D, or 12.5EE, boots after replacing the given footbeds with a thicker alternative.

If these boots would be used for work in a company that helps cover the cost of footwear, let me know before buying so I can ensure you'll receive a proper invoice that can be shown to your employer.