I'm at the height limit for a Regular sleeping bag. Should I 'size up'?

A related question: 'Why don't you quote the overall length of your sleeping bags, rather than publishing a maximum user height?

We publish maximum user height because it’s a more practical way to choose the right size.

• Sea to Summit is an Australian company, so our bags are originally spec’d in metric measurements (later converted to inches for the US).
• The usable length of a sleeping bag isn’t fixed – it depends on how much volume the sleeper takes up and how tightly the hood is cinched. This can change the effective length by up to 4 in / 10 cm.

Which size should I choose if I’m close to the maximum height?

• If you’re at or near the maximum height listed for a Regular, we recommend sizing up to the Long (unless weight is critical, see below). 
• A too-short bag may cause you to compress the insulation in the hood and footbox, which may lead to cold spots.
• Long sizes also provide a bit more girth, which can be helpful if you have a larger body build.

Any exceptions?
Yes. If weight is your top priority – for example, if you’re a thru-hiker or bikepacker looking at ultralight models like the Spark or Spark Pro – you may still choose the Regular size, even at the maximum listed height, to keep your gear as light as possible.