Accessories like rings, hats, and gloves each use their own distinct sizing systems that have little in common with clothing sizes. This guide gives accurate conversion tables for all three, so you can shop confidently whether you're buying a gift or replacing a worn-out item. For garment sizing, see our full size converter.
Ring Size Chart (US, UK, Diameter, Circumference)
Ring sizes are based on the internal diameter and circumference of the ring in millimeters. US sizing uses a numeric scale (often with half sizes), while the UK and much of the Commonwealth use a letter-based scale.
| US Size | UK Size | Diameter (mm) | Circumference (mm) |
|---|---|---|---|
| 4 | H | 14.9 | 46.8 |
| 5 | J 1/2 | 15.7 | 49.3 |
| 6 | L 1/2 | 16.5 | 51.9 |
| 7 | N 1/2 | 17.3 | 54.4 |
| 8 | P 1/2 | 18.1 | 56.9 |
| 9 | R 1/2 | 18.9 | 59.5 |
| 10 | T 1/2 | 19.8 | 62.1 |
| 11 | V 1/2 | 20.6 | 64.6 |
| 12 | Y | 21.4 | 67.2 |
To measure your own ring size at home, wrap a strip of paper or string around the base of your finger, mark where it overlaps, measure that length in millimeters, and match it to the circumference column above.
Hat Size Chart (Head Circumference)
Hat sizes are based on head circumference, measured about an inch above the eyebrows and ears at the widest point of the head. Hats are typically sold in both letter sizes (S, M, L, XL) and traditional numeric US hat sizes, which represent the head diameter in inches.
Looking for a specific brand?
Fit varies far more between brands than between size systems.
Browse 30+ brand size charts| Letter Size | US Hat Size | Head Circumference (in) | Head Circumference (cm) |
|---|---|---|---|
| XS | 6 3/4 | 21.25 | 54 |
| S | 6 7/8 - 7 | 21.6-22 | 55-56 |
| M | 7 1/8 - 7 1/4 | 22.4-22.75 | 57-58 |
| L | 7 3/8 - 7 1/2 | 23.1-23.5 | 59-60 |
| XL | 7 5/8 - 7 3/4 | 23.9-24.25 | 61-62 |
| XXL | 7 7/8 - 8 | 24.6-25 | 63-64 |
To find your hat size, wrap a soft tape measure around your head at that eyebrow-level point, keeping it snug but not tight, then match the result to the chart above.
Glove Size Chart (Hand Circumference)
Glove sizes are based on hand circumference, measured around the widest part of your palm (excluding the thumb), often expressed in inches for both men's and women's gloves.
| Size | Hand Circumference (in) | Hand Circumference (cm) |
|---|---|---|
| XS | 6-6.5 | 15.2-16.5 |
| S | 7-7.5 | 17.8-19 |
| M | 8-8.5 | 20.3-21.6 |
| L | 9-9.5 | 22.9-24.1 |
| XL | 10-10.5 | 25.4-26.7 |
| XXL | 11-11.5 | 27.9-29.2 |
For a snug, functional fit (especially for winter or work gloves), measure around your dominant hand since it's often very slightly larger, and choose the size that matches or rounds up slightly if you'll be wearing a liner underneath.
Tips for Buying Accessories Online
Unlike clothing, accessories generally have less room for "in-between" sizing adjustments, since a ring that's too small won't slide on and a hat that's too tight will be uncomfortable within minutes. Always measure directly rather than guessing from your clothing size, and when in doubt between two sizes, size up for hats and gloves (where a slightly loose fit is more comfortable than tight) but size precisely for rings.
How These Compare Across Categories
It helps to remember that rings, hats, and gloves are measured in three completely different ways: rings by internal diameter or circumference in millimeters, hats by head circumference in inches or centimeters, and gloves by hand circumference in inches. None of these correlate directly with your clothing size (a person who wears a Large shirt could easily have a Small ring size), so always use the specific accessory chart. If you also need help with garment sizing alongside your accessories, our how to measure yourself guide and the size converter cover tops, bottoms, and dresses in detail.
Adjustable Sizes and When They Don't Apply
Many hats and some gloves come in adjustable or "one size fits most" options, typically built to accommodate head circumferences from about 21 to 24 inches or hand circumferences within a moderate middle range. These options are convenient but won't work well for people at the extremes of the sizing spectrum, so if your head circumference is under 21 inches or over 24.5 inches, or your hand circumference falls outside the 7-10.5 inch range, look for a fitted or sized option instead of an adjustable one. Rings are essentially never adjustable in a reliable long-term way (aside from temporary sizing beads or inserts), so always size rings precisely rather than assuming an in-between size will work.
Resizing and Exchange Considerations
If you're ordering rings, hats, or gloves as a gift and can't get a direct measurement, it helps to know that rings can often be resized by a jeweler within a couple of sizes up or down, while hats and gloves generally cannot be resized after purchase and must be exchanged if they don't fit. When in doubt, sizing a ring slightly larger is usually easier and cheaper to fix than sizing it too small, and for hats or gloves, checking the retailer's return policy before buying is a practical safeguard against a mismeasured guess.