The elastic band
Spandex-blend bands cover a span rather than an exact size, which makes them forgiving — but they also relax with age and hot drying. A cap bought at the top of a span will feel looser within a year.
Unofficial guide · not affiliated with Flexfit
Flexfit cap sizes, decoded
Flexfit popularized the stretch-fit system most cap makers now use: an elastic headband and combined letter sizes instead of sewn fractions. There is no official global table — spans differ brand by brand — so the reliable method is to measure your head and compare against each maker's published span.
Stretch-fit spans, as a general guide
| Label | Head circumference (cm) | Head (inches) | ≈ fitted equivalent |
|---|---|---|---|
| S/M | 54–55.9 cm | 21.3–22.0 in | 6 3/4 – 6 7/8 |
| M/L | 56.8–58.7 cm | 22.4–23.1 in | 7 – 7 3/8 |
| L/XL | 59.7–63.5 cm | 23.5–25.0 in | 7 1/2 – 7 7/8 |
Stretch-fit hats use combined sizes (S/M, M/L, L/XL). These bands are a general guide and vary by brand; check the brand's own chart. Checked 2026-10-21. The exact fitted fractions live in thefitted cap size chart.
Stretch-fit vs fitted caps
Sizing between spans
Heads near a span boundary (say 55.9 cm) can go either way: the smaller span grips without sagging, the larger span never pinches. If you wear glasses or a headset often, prefer roominess.
Crown depth still matters
Elastic sizes only handle the ring around the head. Depth (low-profile vs structured) decides whether the cap sits above your ears — combined with your measurement, that's the full fit picture.
Unofficial page — brand names belong to their owners; no logos are used.
Flexfit sizing FAQs
What Flexfit size for a 57 cm head?
M/L is the usual answer — most published stretch-fit spans put M/L around 56.8–58.7 cm, which matches a US fitted 7 1/8 to 7 3/8. Because elastic firms give, a 57 cm head is equally fine in M/L sized spans that start lower; verify the brand's published span.
Are Flexfit sizes the same everywhere?
No — 'Flexfit' is both a brand and a widely adopted fabric system, and labels like S/M and L/XL are used by many makers whose spans differ by a centimetre or more. The head measurement decides, not the letter.
What fitted size is Flexfit's L/XL?
Spans vary by brand, but as a general guide L/XL covers roughly 59.7–63.5 cm — about US 7 5/8 to 7 7/8 on the fitted chart. Check the specific product page; some 'L/XL' hats are labeled differently by region.
How tight should a stretch-fit cap be?
The band should hold without pinching and rebound fully when you take the cap off. A cap that leaves a deep red line is too small even if the span reading says it fits — span tables assume the fabric's elasticity, brand differences included.
Is this page affiliated with Flexfit?
No. Independent and unofficial: a guide to how stretch-fit cap sizing generally works so you can pick between elastic sizes. The maker's official size guide is the authority for a specific product.