Measure around your head just above the ears and enter the circumference to find your fitted hat size. Results include US, UK, metric, and generic S/M/L sizing for easy shopping.
Hat sizing has evolved over centuries with multiple systems still used today. Traditional US hat sizing uses fractional numbers (6¾ to 8 typical adult range), measured by inner circumference. Metric/UK systems use head circumference directly in centimeters. Modern casual hats often use simpler small/medium/large/XL sizing or "one size fits most" adjustable designs. Despite these systems, a properly fitted hat — fitted baseball cap, fedora, cowboy hat, beret — needs accurate sizing for both appearance and comfort.
A well-fitted hat should sit comfortably without leaving a tight indent on the forehead, but shouldn't slip down past the ears or shift in moderate wind. Too tight: headache pressure, marks on forehead. Too loose: constantly needing adjustment, looks sloppy. Fitted baseball caps (popular in sports culture) require precise sizing — there's no adjustment built in. Adjustable caps (snapbacks, strapbacks) accommodate larger size range but never fit as perfectly as a properly-sized fitted cap.
This calculator converts head circumference (in inches or centimeters) to hat sizes across US fractional, UK, EU, and generic S/M/L systems. Use it for: online hat shopping, fitted cap purchases, dress hats for special occasions, or international purchases. Important context: hat sizes vary somewhat across brands and styles. Fitted baseball caps have minimal stretch; structured fedoras have minimal flex; knit beanies stretch substantially. Different hat types may require different effective sizes. For most precise fit: try on at retailer when possible. For online orders: read fit reviews; consider brand-specific sizing notes; account for hat material (wool, straw, cotton, plastic).
Head circumference 22 inches. US hat size: 7 (Medium) UK hat size: 6 7/8 EU/cm size: 56 S/M/L: Medium Most common women's adult size. Wide availability across brands and styles. For fitted baseball cap: New Era 59FIFTY 7 For adjustable cap: standard one-size-fits-most works For knit beanie: Medium For dress hat: 7 (Medium) Brand variation: same person may need 6 7/8 in one brand, 7 in another. Hat shopping requires trying or careful brand-specific chart review.
Head circumference 24 inches (XL range). US hat size: 7 5/8 (Extra Large) UK hat size: 7 1/2 EU/cm size: 61 S/M/L: XL Less commonly stocked size. May need to order online or visit specialty hat shops. Challenges: - Many adjustable caps top out around 24-24.5 inches - Bare minimum: order from brands offering XL or 7 5/8+ - New Era fitted: 7 5/8 = "Big" sizes; available but reduced stock - Trucker hats may be limited - Dress hats: ensure XL options Best brands for XL+ heads: - New Era (offers up to 8+ in many styles) - '47 Brand (XL versions of many caps) - Specialty: Big Head Caps, BigHeadCaps.com Some XL-specific retailers exist serving this market.
Tracking child's hat sizes through ages: Age 0-3 months: 13-14 inches (newborn hat) Age 6 months: 17 inches Age 1 year: 18 inches Age 2 years: 19 inches Age 4 years: 20 inches Age 6 years: 20.5 inches Age 8 years: 21 inches Age 10 years: 21.5 inches Age 12 years: 21.5-22 inches (entering adult range) By teens (14+): most children reach near-adult sizing. For sustainability: buy slightly larger sizes for children to allow growth; expect to replace hats every 1-2 years until adolescence. For specific items (sports caps for league play): size correctly; ill-fitting hats may cause issues during play. Some leagues provide team hats sized to fit. For winter beanies: stretch accommodates growth somewhat; one beanie often lasts 2-3 winters.
Use this calculator for online hat shopping, fitted baseball cap purchases, dress hats for special occasions, international purchases, or gifts where you have head measurement.
Pair with shoe-size, ring-size, and other size calculators.
Important hat sizing considerations:
1. **Fitted caps require precision.** No adjustment built in. Order exact size.
2. **Adjustable hats forgive size variation.** Snapbacks, strapbacks, beanies accommodate range.
3. **Brand sizing varies.** Same number from different brands may fit differently.
4. **Hair affects fit.** Long hair, updos, or thick hair may require larger size.
5. **Materials behave differently.** Stretchy beanies forgive; rigid baseball caps don't.
6. **Measurement varies by 1/8 inch easily.** Multiple measurements for accuracy.
7. **Children outgrow hats fast.** Buy slightly larger; expect replacement.
8. **US fractional and EU mm sizes most precise.** S/M/L generic for casual hats.
9. **Hat stretchers extend life.** $10-$30 device stretches half-size larger.
10. **Sweatbands can adjust fit slightly.** Some hats have removable foam strips.
11. **Custom hats for perfect fit.** $300+ for high-end; worth investment for collectors or special occasions.
12. **Head shape matters too.** Round vs. oval heads fit slightly differently in same size.
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US Fitted Size
7 1/8
Generic Size
M
Inches
22.50
Centimeters
57.1
| Measurement | Value |
|---|---|
| Head Circumference (in) | 22.50 inches |
| Head Circumference (cm) | 57.1 cm |
| US Fitted Size | 7 1/8 |
| Generic Size | M |