Hat size converter
Pick the hat you wear now. Every other brand chart shows which of its own published sizes covers the same head, with the brand's numbers and a link to where they came from.
By Fitness Hats Editorial Team, published October 31, 2026. Brand charts checked October 4, 2026
New Era 59FIFTY fitted lists
7 1/4
for a head of 22 3/4 in, 57.7 cm
| Brand and line | Its size | Published head size | Source |
|---|---|---|---|
| '47 Adjustable caps | WOMEN or OSFAIts range covers your size | WOMEN: 21 1/2 to 23 1/2 in, 55 to 59 cmOSFA: 22 to 24 in, 56 to 61 cm | '47 chartchecked 2026-10-04 |
| adidas Hats and caps | Adult (S/M)Its range covers your size | Adult (S/M): 22 to 22.8 in, 56 to 58 cm | adidas chartchecked 2026-10-04 |
| Arc'teryx Hats and caps | One-size-fits-allIts range covers your size | One-size-fits-all: 21 3/4 to 23 1/2 in, 55 to 60 cm | Arc'teryx chartchecked 2026-10-04 |
| Boco Gear Hats | OSFMIts range covers your size | OSFM: 55 to 59 cm | Boco Gear chartchecked 2026-10-04 |
| Ciele Athletics GOCap, FSTCap and TRLCap | S/M or M/L or L/XLIts range covers your size | S/M: 53.5 to 59 cmM/L: 55 to 61 cmL/XL: 57 to 63 cm | Ciele Athletics chartchecked 2026-10-04 |
| Flexfit Standard stretch-fit | S/M or OSFA or L/XLIts range covers your size | S/M: 21 1/4 to 22 3/4 in, 54 to 58 cmOSFA: 21 5/8 to 23 1/2 in, 55 to 60 cmL/XL: 22 3/8 to 23 7/8 in, 57 to 61 cm | Flexfit chartchecked 2026-10-04 |
| Flexfit DELTA (stretch-fit) | S/M or L/XLIts range covers your size | S/M: 21 1/4 to 22 3/4 in, 54 to 58 cmL/XL: 22 3/8 to 23 7/8 in, 57 to 61 cm | Flexfit chartchecked 2026-10-04 |
| Flexfit 210 (stretch-fit) | S/MIts range covers your size | S/M: 21 5/8 to 22 3/4 in, 55 to 58 cm | Flexfit chartchecked 2026-10-04 |
| Flexfit 110 (adjustable) | OSFAIts range covers your size | OSFA: 20 3/8 to 24 5/8 in, 52 to 63 cm | Flexfit chartchecked 2026-10-04 |
| Headsweats Large Running Hat | LargeIts range covers your size | Large: 57 to 63 cm | Headsweats chartchecked 2026-10-04 |
| King & Fifth Adjustable caps | S/MIts range covers your size | S/M: 21 3/4 to 22 3/4 in, 55.1 to 58 cm | King & Fifth chartchecked 2026-10-04 |
| King & Fifth The Jack (fitted) | MIts range covers your size | M: 22 1/2 to 23 1/8 in, 57 to 58.9 cm | King & Fifth chartchecked 2026-10-04 |
| Lamood Big Hats Size chart | Not on this chart. Smallest listed: 7 1/4. | 7 1/4: 22 3/4 to 22 7/8 in, 57.8 to 58.1 cm | Lamood Big Hats chartchecked 2026-10-04 |
| lululemon Hats in S/M and L/XL | S/M or L/XLIts range covers your size | S/M: 20.06 to 23 1/4 in, 51 to 59 cmL/XL: 22.44 to 24 3/8 in, 57 to 64 cm | lululemon chartchecked 2026-10-04 |
| lululemon Hats in XS to XL | LIts range covers your size | L: 22.44 to 23 1/4 in, 57 to 59 cm | lululemon chartchecked 2026-10-04 |
| Mammoth Headwear Regular and XXL caps | Not on this chart. Smallest listed: Regular Size. | Regular Size: 24 1/4 to 26 7/8 in, 61.4 to 68.3 cm | Mammoth Headwear chartchecked 2026-10-04 |
| Melin Size guide (all caps) | SMALLIts range covers your size | SMALL: 22 to 22 5/8 in, 56.5 to 58.5 cm | Melin chartchecked 2026-10-04 |
| New Era 39THIRTY stretch-fit | S/MIts range covers your size | S/M: 22 3/8 to 23 1/8 in, 56.8 to 58.7 cm | New Era chartchecked 2026-10-04 |
| New Era 9FIFTY snapback | S/M or One Size or M/LIts range covers your size | S/M: 21 5/8 to 23 1/2 in, 54.9 to 59.6 cmOne Size: 22 3/8 to 24 5/8 in, 56.8 to 62.5 cmM/L: 22 3/8 to 24 5/8 in, 56.8 to 62.5 cm | New Era chartchecked 2026-10-04 |
| New Era 9FORTY adjustable | One SizeIts range covers your size | One Size: 22 to 23 7/8 in, 55.8 to 60.6 cm | New Era chartchecked 2026-10-04 |
| New Era 9TWENTY and Casual Classic | One Size Fits MostIts range covers your size | One Size Fits Most: 22 to 23 7/8 in, 55.8 to 60.6 cm | New Era chartchecked 2026-10-04 |
| Nike Adjustable caps | M/L or ONE SIZEIts range covers your size | M/L: 21 1/2 to 23 1/2 in, 55 to 60 cmONE SIZE: 21 1/2 to 23 1/2 in, 55 to 60 cm | Nike chartchecked 2026-10-04 |
| Nike Swoosh Flex (stretch-fit) | M/LIts range covers your size | M/L: 21 7/8 to 23 in, 56 to 59 cm | Nike chartchecked 2026-10-04 |
| On Caps (one size) | ONE SIZEIts range covers your size | ONE SIZE: 21.7 to 23.6 in, 55 to 60 cm | On chartchecked 2026-10-04 |
| On Caps in S/M and L/XL | L/XLIts range covers your size | L/XL: 21.7 to 23.6 in, 55 to 60 cm | On chartchecked 2026-10-04 |
| Patagonia Hats (all styles) | Small/Medium or One SizeIts range covers your size | Small/Medium: 21 3/4 to 22 3/4 inOne Size: 21 3/4 to 24 in | Patagonia chartchecked 2026-10-04 |
| Richardson Fitted | No size lists this head. Between 7 1/8 and 7 1/4. | 7 1/8: 22 3/8 in, 57 cm7 1/4: 22 3/4 in, 58 cm | Richardson chartchecked 2026-10-04 |
| Richardson R-Flex (stretch-fit) | SM-MDIts range covers your size | SM-MD: 22 to 22 3/4 in, 56 to 58 cm | Richardson chartchecked 2026-10-04 |
| Richardson Adjustable | OSFM & MD-LGIts range covers your size | OSFM & MD-LG: 22 to 24 1/4 in, 56 to 62 cm | Richardson chartchecked 2026-10-04 |
| Richardson System 5 (PTS75) | MDIts range covers your size | MD: 22 3/8 to 22 3/4 in, 57 to 58 cm | Richardson chartchecked 2026-10-04 |
| Under Armour Men's and unisex headwear | OSFM or M/LIts range covers your size | OSFM: 21 5/8 to 23 7/8 in, 54.9 to 60.6 cmM/L: 22 to 23 1/4 in, 55.9 to 59.1 cm | Under Armour chartchecked 2026-10-04 |
| Under Armour Hat size table | 7 1/4Same head size | 7 1/4: 22 3/4 in, 57.8 cm | Under Armour chartchecked 2026-10-04 |
The tool opens on New Era 59FIFTY fitted size 7 1/4 as an example; choose yours. Don't know your head size? Use the hat size chart.
Download the tables
Generated from the same charts as the tool, on every build. Save them, print them, or load the CSV into a spreadsheet.
- Published charts (CSV) 31 KB177 rows: every size row of every chart exactly as printed, with the source URL and the date checked. Nothing computed.
- Cross-brand table (CSV) 1078 KB4448 rows: every size on every chart against every other chart, with the published numbers behind each answer.
- Conversion card, US Letter (PDF) 10 KBUS sizes against the head size each main brand publishes. One page to keep in a bag or print for shopping.
- Conversion card, A4 (PDF) 10 KBThe same card on A4 paper.
The cross-brand table is computed by the rules below from the published rows in the first file. Both name the chart page and the date each row was read.
US sizes against each brand's published head size
The printable card, as a table. Brand columns are copied from each brand's chart; the second column is computed.
| US size | By convention (cm) | New Era 59FIFTY fitted | Richardson Fitted | Under Armour Hat size table | Lamood Big Hats Size chart |
|---|---|---|---|---|---|
| 6 3/8 | 50.9 | 51 cm | |||
| 6 1/2 | 51.9 | 52 cm | |||
| 6 5/8 | 52.9 | 53 cm | 53 cm | ||
| 6 3/4 | 53.9 | 54 cm | 54 cm | ||
| 6 7/8 | 54.9 | 54.9 cm | 55 cm | 54.9 cm | |
| 7 | 55.9 | 55.8 cm | 56 cm | 55.9 cm | |
| 7 1/8 | 56.9 | 56.8 cm | 57 cm | 56.8 cm | |
| 7 1/4 | 57.9 | 57.7 cm | 58 cm | 57.8 cm | 57.8 to 58.1 cm |
| 7 3/8 | 58.8 | 58.7 cm | 59 cm | 58.7 cm | 58.2 to 59.1 cm |
| 7 1/2 | 59.8 | 59.6 cm | 60 cm | 59.7 cm | 59.2 to 60 cm |
| 7 5/8 | 60.8 | 60.6 cm | 61 cm | 60.6 cm | 60.1 to 61.3 cm |
| 7 3/4 | 61.8 | 61.5 cm | 62 cm | 61.6 cm | 61.4 to 62.2 cm |
| 7 7/8 | 62.8 | 62.5 cm | 63 cm | 62.5 cm | 62.3 to 63.2 cm |
| 8 | 63.8 | 63.5 cm | 64 cm | 63.5 cm | 63.3 to 64.1 cm |
| 8 1/8 | 64.8 | 64.5 cm | 64.2 to 65.1 cm | ||
| 8 1/4 | 65.8 | 65.4 cm | 65.2 to 66 cm | ||
| 8 3/8 | 66.8 | 66.1 to 67 cm | |||
| 8 1/2 | 67.8 | 67.1 to 68.3 cm | |||
| 8 5/8 | 68.8 | 68.4 to 69.2 cm | |||
| 8 3/4 | 69.8 | 69.3 to 70.2 cm | |||
| 8 7/8 | 70.8 | 70.3 to 71.1 cm | |||
| 9 | 71.8 | 71.2 to 72.1 cm | |||
| 9 1/8 | 72.8 | 72.2 to 73.1 cm | |||
| 9 1/4 | 73.8 | 73.2 to 74.1 cm |
How a size is converted
Every size on a chart stands for a head range: a single published value for a fitted cap, or a published minimum and maximum for stretch-fit and adjustable caps. Inch-only rows are converted at 2.54 cm per inch for the comparison only. The tool then compares your size's range with every size on the other chart:
- Same head size. Both charts list one head size, and they are within 0.2 cm of each other (brands publish to 0.1 cm).
- Its range covers your size. The other size is a range that includes your size, or your size is a range inside it.
- Falls inside your size’s range. Your size is a range and the other chart’s single published value falls within it, or its range sits inside yours.
- Ranges partly overlap. Two ranges share some heads but neither contains the other, so the fit at the edges can differ.
When nothing overlaps, you see the two published sizes on either side, or the largest or smallest size that chart lists. A conversion tells you which published size is cut for the same head. It does not say how a particular hat sits, which depends on the hat's construction; that is what our measurements will cover once hats are measured. Sources for every chart are on the brand pages, and the convention behind US sizes is on the fitted hat size chart.
Charts in this tool: 33 from 21 brands. A chart is left out only if it contradicts itself; the reason is shown on the hat size chart. Convention source: Wikipedia, Hat: Size.
Frequently asked questions
Is a 7 1/4 the same head size in every brand?
Mostly, for fitted caps. For 7 1/4, Lamood Big Hats Size chart lists 22 3/4 to 22 7/8 in, 57.8 to 58.1 cm; New Era 59FIFTY fitted lists 22 3/4 in, 57.7 cm; Pacific Headwear True fitted lists 22 3/4 in, 58 cm; Richardson Fitted lists 22 3/4 in, 58 cm; Under Armour Hat size table lists 22 3/4 in, 57.8 cm. Stretch-fit, adjustable and letter sizes have no common standard, which is why the converter compares published head ranges instead of labels.
How does the converter pick a size in another brand?
It takes the head range your size stands for on its own chart, then lists every size on the other chart whose published range covers it, falls inside it, or overlaps it. If no size does, it shows the published sizes on either side and says so. It never invents a size a brand did not publish.
What head size is S/M?
It depends on the brand. Across the 12 charts we checked that use S/M, it covers heads from 51.0 to 59.6 cm. Ciele Athletics GOCap, FSTCap and TRLCap: 53.5 to 59 cm; Flexfit Standard stretch-fit: 21 1/4 to 22 3/4 in, 54 to 58 cm; Flexfit DELTA (stretch-fit): 21 1/4 to 22 3/4 in, 54 to 58 cm; Flexfit 210 (stretch-fit): 21 5/8 to 22 3/4 in, 55 to 58 cm; King & Fifth Adjustable caps: 21 3/4 to 22 3/4 in, 55.1 to 58 cm; lululemon Hats in S/M and L/XL: 20.06 to 23 1/4 in, 51 to 59 cm; New Era 39THIRTY stretch-fit: 22 3/8 to 23 1/8 in, 56.8 to 58.7 cm; New Era 9FIFTY snapback: 21 5/8 to 23 1/2 in, 54.9 to 59.6 cm; Nike Adjustable caps: 20 1/2 to 22 1/4 in, 52 to 57 cm; Nike Swoosh Flex (stretch-fit): 20 7/8 to 21 7/8 in, 53 to 56 cm; On Caps in S/M and L/XL: 20 1/2 to 22.4 in, 52 to 57 cm; Under Armour Men's and unisex headwear: 21 1/4 to 22 1/2 in, 54 to 57.2 cm. 2 more charts use the label but are left out because they contradict themselves; the reason is in the table.
Should I size up or down when brands disagree?
Trust your own measurement and the brand’s own chart for the hat you are buying. Where a brand says which way to go between sizes, the calculator and the chart pages quote it. The converter is for finding a starting point on a chart you have not used before.
Keep going
- Head Circumference to Hat Size Chart, in cm and Inches
Head circumference in half-centimeter and quarter-inch steps, with the hat size each brand chart lists for it. Download the lookup table as CSV.
- Fitted Hat Size Chart: 59FIFTY and Other Fitted Caps
Fitted cap sizes by brand, from each brand’s own chart: the head size every label is cut for, in inches and cm, and how stretch-fit sizes compare.
- Hats for Big Heads: Which Brand Charts Go Up to Your Size
Enter your head size and see which brands publish a hat size that covers it, the largest size each chart lists, and the source page for every number.
- Printable Head Measuring Tape (Calibrated PDF)
A free printable tape for measuring your head for a hat: 0 to 72 cm with inches, on Letter or A4, with a bank-card and 10 cm check for print scale.