If you’ve knit even one sweater, you’ve probably noticed this: the sleeve length, as written in the pattern, almost never matches your arms perfectly.

Maybe your sleeves are always a little too short. Or maybe you keep rolling the cuffs up because they’re too long.

Either way, it’s not you—and it’s not necessarily the pattern.

Have you ever knit a sweater, finished it, blocked it (eek, it looks so good!!), and then tried it on—only to realize it doesn’t fit? Maybe it pulls at the underarms, the neckline sits strangely, or the whole garment feels too tight…or too loose.

Or maybe you’re about to cast on your first garment and feel stuck before you even begin: Which size should I choose?