Everyone sleeps differently, so finding a single size that works for all doesn’t really cut it. That’s why we let you dial in the fit to suit your own sleep style and body shape. Length refers to the total distance from the bottom of the footbox to the cinch cord at the neck. A standard-length quilt provides full coverage, including your head, matching your full body length. For a performance fit, you can choose a quilt up to 15 cm shorter than your body length to save a few grams and get a tighter fit around the feet. If you usually sleep on your stomach, consider adding about 5 cm for extra toe room. Upper width is measured around the widest part of your body, arms included, while lying in your normal sleeping position. Slim is usually a good fit up to 127 cm, regular works well from 127 to 137 cm, and wide is ideal for 137 to 147 cm. If you move around at night, a bit of extra width can help keep drafts out and give you more wiggle room. Footbox width comes down to how much space you like around your legs and feet. Basically everyone will physically fit in a slim (96cm) footbox, but if you prefer more space or tend to shift a lot in your sleep, consider regular (102 cm) or wide (112 cm).