Having the correct size of sleeping bag is arguably more important than in any other type of product, since how well a bag fits you has a direct correlation to the thermal efficiency of that bag. Too large and it will take longer for your body to warm up, too small and the filling will be compressed and not retain enough heat.

Now before we get carried away, lets be honest here. The availability of sizes in products is linked partly to potential and actual demand, potentially a viscious circle I can hear you cry. But ultimately the potential and actual volume of sales is the major reason why large High Street retailers for example can offer products but particularly clothing in many different size options, since they know they will sell many hundreds of thousands of items.
Transfer that growing expectation into outdoor retail and you find a potential source of some frustration, since whilst the choice of sizing in clothing has improved as the market has become larger, the choice of size options has never (and arguably will never) quite match that of the general high street.
Equally with sleeping bags, in fact more so, the specialist outdoor market is never going to be that large, but in many cases, there is enough demand. Every week we get enquiries from people concerned that they are too tall to fit inside a regular length sleeping bag, in most cases these are enquiries from people in excess of 6ft 1", not that uncommon these days, wanting to know firstly if we make longer bags and secondly whether anyone actually stocks them. In fact these enquiries vastly outnumber the enquiries we have from people wanting to know if we manufacture womens specific bags.
Well the answer to that question, is yes we do.
Mountain Equipment produces the vast majority of its sleeping bags in both regular and XL versions (which are both longer and slightly wider) and in some cases we produce shorter or junior bags also, in addition to a number of women's specific models. Yet in the UK few retailers choose to stock them? Walk into a shop in Germany and you would find a very different scene, Mountain Equipment bags stocked in Short, Regular and Extra Long and more importantly, customers actually asking, indeed demanding to see the sizes of bag in stock.

So remember size does matter, if you're particularly tall then XL bags are available, you may need to convince your local retailer to order one especially or track one down via one of our online stockists, but if you do not ask, they will not stock and you may potentially end up with a sleeping bag that doesnt perform quite as well as it should.
http://www.mountain-equipment.co.uk/the_gear/down_sleeping_bags/
http://www.mountain-equipment.co.uk/the_gear/synthetic_sleeping_bags/