Toe and heel drag occur when your toes or heels hang over the edge of the board. This in itself is not necessarily a big problem, but as soon as you start tilting a board onto it's edge more, then your toes or heels can drag in the snow lifting the edge of the board away from the snow and meaning you lose grip and wipe out. The situations in which your board would be at such an edge angle is when you are riding steep terrain or you are doing very low carves. These are both quite advanced skills, which is why beginners are often ok on a board that is too narrow for them at first, but then as they progress they begin to have the toe/heel drag problem.
Ok, so why don't we all just ride super wide snowboards to avoid this problem? Well, as you may well realise, a wide snowboard makes it more difficult to initiate an edge change, therefore making it more difficult to turn. So here we must now find the perfect waist width for our board in relation to our feet. With only a couple of centimetres separating what would be considered a narrow and a wide board, the minor differences in numbers here can make a big difference to your riding.
Waist width: 240mm - 245mm
UK Boot size: > 6
Waist width: 245mm - 255mm
UK Boot size: 7 - 9
Waist width: 255mm - 265mm
UK Boot size: 10 - 11
Waist width: 265mm - 270mm+
UK Boot size: 12+
Above is a rough guide to help you out. However as with anything it's not always that black and white. Firstly your riding style can play a factor. Do you like to lay out euro carves on your belly? Then toe or heel overhang is not an option and you need a board plenty wide enough. However, if you spend most of your time jibbing in the park, and staying away from steep slopes, then a bit of toe overhang may not affect your riding.
Next up is the angles of your bindings. The more your feet are angled out, the less space they will take up going across the board. For instance if you have angles of +15 and -15 degrees you will have less overhang than if you set your back flat at 0 degrees as some people like.
The next factor for me is a big one; boots. Some brands offer 'reduced footprint' boots. They have been clever at reducing the amount of materials required at the back and the front of the boot, ending up with a boot as short as it can possibly be for your foot size. I always ride Burton Boots now, as their reduced footprint technology is very good. I once purchased some Salomon boots in a size 11 UK and they were a whole cm longer than my Burtons of the same size! If you have larger feet I would definitely look at a brand offering this technology.
So now if you know you need a wider board start paying attention to the waist width listed on the spec sheet. Also beware that some brands say a board is wide but it actually may not be wide enough, and could be what some brands call mid-wide.
I have size 11 UK feet and I am currently on a stepchild board with a 264mm waist. I prefer to go slightly wider than the chart above advises because just about my favourite thing to do on a snowboard is lay out a belly scratching euro carve where my board is angled right up on its edge. Toe drag here, which still sometimes happens, can quickly see you go from hero to zero.
Finding wider boards with a 260mm plus waist can be difficult. In my experience I have found that Rome, Never Summer, Bataleon and Stepchild make good wide boards that are actually wide enough. Other brands offer good boards around the 260mm mark, whilst some brands don't offer anything wide at all!
Finally I would like to mention slightly more unconventional boards. Recently there has been a big trend to shorter fatter boards, spearheaded alot by K2. Originally the idea was to combine the surface area of a longer board into a much shorter one, allowing the same float in powder whilst being more manouverable in tight situations. However, as not every day is a powder day, brands started to realise that these boards could also be incredibly fun on piste. Their wide waists, often over 27cm, allowing for deep carves with no chance of toe or heel drag. Boards like this include the K2 party platter, cool bean, eightyseven, and simple pleasures. Also the Spring Break slush slasher, and Never Summer Instagator to name a few.
Now these boards may not be for everyone, perhaps too directional in shape, or not ideal in the park. However, they can provide an interesting alternative particularly if your board options are limited due to the fact having a waist width of over 260mm, for example, is a necessity.
I hope this made sense! If you need any advice, ping me an email, I'm always happy to talk board shapes and sizes!