Hat Size Chart: Complete Sizing Guide for Inches, CM, US, UK & EU
Hat sizing converts head circumference into US, UK, and EU labels. Measure around the forehead, just above the ears, then use the conversion chart for your hat type.
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Ordering custom hats without a reliable size chart is a fast way to burn through your MOQ budget. A batch of caps that fits too tight or too loose means returns, exchanges, and brand damage — problems no apparel buyer wants to explain to their customers.
A hat size chart converts a simple head circumference measurement into the correct hat size across US, UK, EU, and general sizing systems. Whether you are sourcing baseball caps, knit beanies, bucket hats, or fedoras, the right chart keeps your size grading accurate from sample to bulk production.
This guide brings every hat sizing system into one place — measurement method, full conversion tables, hat-type-specific sizing, and age-based charts for kids and crochet projects.
Quick Hat Size Conversion Table
Use this master table to convert head circumference into US hat size, general size label, and metric (CM).
| Head (Inches) | US Hat Size | General Size | Metric (CM) |
|---|---|---|---|
| 20 1/4 | 6 3/8 | XS | 51 |
| 20 5/8 | 6 1/2 | XS | 52 |
| 20 7/8 | 6 5/8 | S | 53 |
| 21 1/8 | 6 3/4 | S | 54 |
| 21 1/2 | 6 7/8 | S | 55 |
| 21 7/8 | 7 | M | 56 |
| 22 1/4 | 7 1/8 | M | 57 |
| 22 5/8 | 7 1/4 | L | 58 |
| 23 | 7 3/8 | L (most common men's) | 59 |
| 23 1/2 | 7 1/2 | XL | 60 |
| 23 7/8 | 7 5/8 | XL | 61 |
| 24 1/4 | 7 3/4 | XXL | 62 |
| 24 5/8 | 7 7/8 | XXL | 63 |
| 25 | 8 | XXL | 64 |
| 25 1/2 | 8 1/8 | XXXL | 65 |
Rule of Thumb: If your measurement falls between two sizes, go up one size for a looser fit or down one size for a snug fit.
Need custom hats graded to these exact sizes? Talk to our team about your size range, fabric, and target market.
How to Measure Your Head for a Hat
Tools and Measurement Position
You need a flexible measuring tape or a piece of string and a ruler.
Wrap the tape around the widest part of your head — across the mid-forehead and about 1/8 to 1 inch above the ears. Keep the tape snug but not tight.
Factory Tip: Measure twice. A 1/4-inch difference can shift the hat size by a full increment.
Sizing Rule: Between Two Sizes
When your measurement lands between two sizes:
Snug fit: Choose the smaller size
Loose fit: Choose the larger size
Default: Go up one size — a slightly loose hat can be adjusted with interior sizing bands, but a tight hat cannot be stretched reliably
Quick formula: Divide head circumference in inches by 3.14, then round up to the nearest 1/8 inch. This gives you the US dress hat size.
US, UK, and EU Hat Size Conversion
Different regions use different hat sizing systems. This table aligns all three so you can convert between them.
| EU Size (CM) | US Size | UK Size | Head Circumference (Inches) |
|---|---|---|---|
| 53 | 6 5/8 | 6 1/2 | 20 1/2 – 20 7/8 |
| 54 | 6 3/4 | 6 5/8 | 21 1/8 |
| 55 | 6 7/8 | 6 3/4 | 21 1/2 |
| 56 | 7 | 6 7/8 | 21 7/8 |
| 57 | 7 1/8 | 7 | 22 1/4 |
| 58 | 7 1/4 | 7 1/8 | 22 5/8 |
| 59 | 7 3/8 | 7 1/4 | 23 |
| 60 | 7 1/2 | 7 3/8 | 23 1/2 |
| 61 | 7 5/8 | 7 1/2 | 23 7/8 |
| 62 | 7 3/4 | 7 5/8 | 24 1/4 |
| 63 | 7 7/8 | 7 3/4 | 24 5/8 |
| 64 | 8 | 7 7/8 | 25 |
| 65 | 8 1/8 | 8 | 25 1/2 |
EU sizing is based on head circumference in centimeters. US sizing uses fractional sizes from 6 3/8 to 8 1/8. UK sizing runs approximately 1/8 size smaller than US.
Hat Size Chart by Hat Type
Baseball Cap and Snapback Size Chart
Adjustable baseball caps and snapbacks use size ranges rather than fixed sizes.
| Size Range | US Hat Size | Head Circumference (Inches) |
|---|---|---|
| S/M | 6 1/2 – 7 1/8 | 20 1/2 – 22 5/8 |
| M/L | 6 7/8 – 7 1/2 | 21 1/2 – 23 1/2 |
| L/XL | 7 1/4 – 8 | 22 5/8 – 25+ |
Most adjustable caps use a strap, snap, or slider to fine-tune the fit within the range.
Fitted Hat Size Chart
Fitted caps require exact sizing because they have no adjustment mechanism.
| US Size | General Size | Head (Inches) | Head (CM) |
|---|---|---|---|
| 6 5/8 – 6 3/4 | S | 20 7/8 – 21 1/8 | 53 – 54 |
| 6 7/8 – 7 | M | 21 1/2 – 21 7/8 | 55 – 56 |
| 7 1/8 – 7 1/4 | L | 22 1/4 – 22 5/8 | 57 – 58 |
| 7 3/8 – 7 1/2 | XL | 23 – 23 1/2 | 59 – 60 |
| 7 5/8 – 7 3/4 | XXL | 23 7/8 – 24 1/4 | 61 – 62 |
Buyer Check: When ordering fitted caps, always specify exact US sizes (e.g., 7 1/4) rather than S/M/L ranges. This prevents grading errors in production.
Flex Hat and Stretch-Fit Size Chart
Stretch-fit caps use elastic bands woven into the sweatband, allowing each size to cover a range.
| Size Range | US Hat Size | Head (Inches) |
|---|---|---|
| S/M | 6 5/8 – 7 | 20 7/8 – 21 7/8 |
| M/L | 7 1/8 – 7 3/8 | 22 1/4 – 23 |
| L/XL | 7 1/2 – 8 | 23 1/2 – 25+ |
Beanie and Knit Hat Size Chart
Knit beanies typically use one-size-fits-most construction, relying on the natural stretch of knitted fabric.
| Size | US Hat Size | Head (CM) |
|---|---|---|
| One Size (OSFM) | 6 1/2 – 7 7/8 | 52 – 63 |
Rule of Thumb: Rib-knit beanies stretch more than jersey-knit styles. If your target market includes larger head sizes, specify a rib-knit construction.
Bucket Hat Size Chart
Bucket hats use fixed or range-based sizing depending on the brim style and fabric.
| Size | US Hat Size | Head (Inches) |
|---|---|---|
| XS/S | 6 5/8 – 6 7/8 | 20 7/8 – 21 1/2 |
| S | 6 5/8 – 6 3/4 | 20 7/8 – 21 1/8 |
| M | 7 – 7 1/8 | 21 7/8 – 22 1/4 |
| L | 7 3/8 – 7 1/2 | 23 – 23 1/2 |
| XL/XXL | 7 7/8 – 8 | 24 5/8 – 25+ |
Fedora and Wide-Brim Hat Sizing
Fedora, wide-brim, and soft felt hats use the same head circumference measurement as baseball caps. The US fractional size (7, 7 1/4, 7 3/8, etc.) applies universally across dress and casual hat styles.
Wide-brim hats, fedoras, and soft felt hats share the same sizing system as baseball caps — there is no separate size chart needed.
Men's vs Women's Hat Sizing
The measurement method is identical for men and women — head circumference determines the hat size regardless of gender.
The practical difference is average head size:
| Group | Common US Size | Head (Inches) |
|---|---|---|
| Men (average) | 7 – 7 3/8 | 21 7/8 – 23 |
| Women (average) | 6 7/8 – 7 1/8 | 21 1/2 – 22 1/4 |
Rule of Thumb: Women's hat lines often use S/M/L labeling. Convert using the general size column in the master table above.
Kids, Youth, and Infant Hat Size Chart
Baby and Newborn Hat Sizes
| Age | Head (Inches) | Head (CM) | General Size |
|---|---|---|---|
| Newborn (0–1 month) | 13 – 14 | 33 – 36 | Newborn |
| 1–3 months | 14 – 15 | 36 – 38 | 0–3M |
| 3–6 months | 15 – 16 1/2 | 38 – 42 | 3–6M |
| 6–12 months | 16 1/2 – 18 | 42 – 46 | 6–12M |
| 12–24 months | 18 – 19 1/2 | 46 – 50 | 12–24M |
Youth and Children Hat Sizes
| Age | US Hat Size | Head (Inches) | Head (CM) |
|---|---|---|---|
| 2–4 years | 6 – 6 1/4 | 19 1/2 – 20 | 50 – 51 |
| 4–7 years | 6 1/4 – 6 1/2 | 20 – 20 5/8 | 51 – 52 |
| 7–10 years | 6 1/2 – 6 5/8 | 20 5/8 – 20 7/8 | 52 – 53 |
| 10+ years (youth) | 6 5/8 – 7 1/8 | 20 7/8 – 22 1/4 | 53 – 57 |
Youth fitted caps typically range from 6 3/8 to 7 1/8 (53–57 CM).
Crochet and Knit Baby Hat Size Chart
Crochet and hand-knit baby hats follow age-based sizing since they rely on stretch.
| Age | Head (CM) | Hat Circumference (CM) |
|---|---|---|
| Preemie | 30 – 34 | 26 – 30 |
| Newborn | 34 – 37 | 30 – 33 |
| 0–3 months | 37 – 40 | 33 – 36 |
| 3–6 months | 40 – 43 | 36 – 39 |
| 6–12 months | 43 – 47 | 39 – 42 |
| 12–24 months | 47 – 50 | 42 – 45 |
Rule of Thumb: For crochet and knit hats, make the hat circumference 1–2 inches (2.5–5 CM) smaller than the head circumference. The fabric stretches to create a snug fit.
Crochet, Knit, and Loom Hat Size Chart
Crochet Hat Size Chart by Age
| Age Group | Head (Inches) | Hat Circumference (Inches) | Hat Height (Inches) |
|---|---|---|---|
| Newborn | 13 – 14 | 11.5 – 12.5 | 5.5 – 6 |
| 3–6 months | 15 – 16.5 | 13.5 – 14.5 | 6.5 – 7 |
| 6–12 months | 16.5 – 18 | 14.5 – 16 | 7 – 7.5 |
| 1–3 years | 18 – 19.5 | 16 – 17.5 | 7.5 – 8 |
| 3–10 years | 19.5 – 20.5 | 17.5 – 18.5 | 8 – 8.5 |
| Teen / Adult | 21 – 23 | 19 – 21 | 8.5 – 11 |
| Large Adult | 23+ | 21+ | 11 – 12 |
Loom Knitting Hat Size Chart
Loom knitting uses peg count and loom diameter to control hat size.
| Loom Size | Peg Count | Hat Size | Fits Head (Inches) |
|---|---|---|---|
| Mini (newborn) | 24 | Newborn | 13 – 14 |
| Small (baby) | 36 | 3–12 months | 15 – 18 |
| Medium (child) | 41 | 1–5 years | 18 – 20 |
| Regular (adult) | 41 – 48 | Adult | 21 – 23 |
| Large (adult XL) | 48 – 60 | Adult XL | 23+ |
Knitting Machine Hat Sizes
Circular knitting machines (commonly 40-needle, 46-needle, or 48-needle models) produce tube-knit hats that stretch to fit.
| Machine Type | Needle Count | Hat Size | Fits Head (CM) |
|---|---|---|---|
| Small | 40 | Baby / Child | 40 – 48 |
| Medium | 46 | Youth / Adult S | 48 – 55 |
| Large | 48 | Adult M – L | 52 – 58 |
Factory Tip: Machine-knit hats rely on yarn stretch. Use ribbed patterns for better elasticity across a wider size range.
General Adult Hat Size Ranges Summary
Use this table when specifying size grading for production orders.
| Size Group | US Hat Size | Head (CM) |
|---|---|---|
| XS/S | 6 3/8 – 6 7/8 | 52 – 55 |
| S/M | 6 7/8 – 7 1/4 | 55 – 58 |
| M/L | 7 1/8 – 7 1/2 | 57 – 60 |
| L/XL | 7 3/8 – 7 3/4 | 59 – 62 |
| One Size (OSFM) | 7 1/8 – 7 1/2 | 57 – 60 |
| Youth OSFM | 6 5/8 – 7 1/8 | 53 – 57 |
Military-style caps follow a similar range, from XS (6 1/2, 20 1/2 inches) to XL (7 3/4, 24 3/8 inches), covering 52–62 CM.
SuhuCustom Custom Hat Manufacturing Support
SuhuCustom is a source apparel factory based in Humen, Dongguan, China, providing OEM/ODM custom manufacturing for knitted hats, baseball caps, bucket hats, and team apparel.
When you need custom hat production, SuhuCustom helps with:
Size grading support — send your target size range and head circumference specs; the team confirms grading before sampling
Sample development — hat samples are typically ready within 3-7 days, depending on design complexity and material availability
Fabric and knit selection — cotton, acrylic, wool blends, and performance fabrics sourced through local supply chains
Logo decoration — embroidery, screen printing, heat transfer, and woven labels
Flexible MOQ — small-batch trial orders are available before committing to bulk production
Quality control — fabric checks, color consistency, shrinkage control, and final inspection before shipment
Private-label packaging — custom labels, hang tags, and packaging for brand-ready delivery
Design confidentiality — agreement available to protect your original designs
Send your hat specifications, size chart, fabric preferences, and logo artwork to get a factory-direct quote.
Buyer Checklist: What to Prepare Before Ordering Custom Hats
Hat type (baseball cap, beanie, bucket, fedora, etc.)
Target size range (US sizes or head circumference in CM)
Size grading breakdown (how many sizes, what intervals)
Fabric or yarn preference (cotton, acrylic, wool blend, performance knit)
Logo artwork file and preferred decoration method
Color palette with Pantone references if possible
Target quantity per size
Sample reference or tech pack
Packaging requirements (labels, hang tags, poly bags)
Delivery timeline and target market
Start Your Free Quote
Ready to produce custom hats with accurate sizing? Send your specifications to SuhuCustom:
Hat type and target size range
Fabric or yarn preferences
Logo artwork and decoration method
Target quantity per size
Packaging and labeling requirements
Delivery timeline
SuhuCustom provides factory-direct pricing, sample development in 3-7 days, flexible MOQ, and one-to-one export support from our Humen, Dongguan team.
