The short answer
In this chart, a chain's thickness means its width. That's the measurement across the outside of its widest link, the convention Rio Grande's chain guide uses. As a chain thickness chart for men, our stock reads like this: 2–3.5mm is a fine line that carries most pendants, 5–6mm makes the link pattern the point, 7–8mm is worn on its own, and 18mm is a collar of silver.
Two chains listed a millimeter apart can look and feel nothing alike. Our 6mm rolo chain is listed at 50 grams; our 7mm Byzantine is listed at about 153 grams. One extra millimeter on paper, roughly three times the listed weight — the Byzantine packs interlinked ring pairs into its width, while a rolo is a single run of oval links.
This chart covers the widths we have in stock as of October 2026, from 2mm up to 18mm, with each chain's listed weight and whether it takes a pendant. Length is its own decision, and our guide to men's chain length walks through it inch by inch. Settle that first, then come back for the width.
The Chain Thickness Chart: 2mm to 18mm Side by Side
Read the bars as a men's chain size chart in millimeters. They share one scale, so the 18mm band is nine times the height of the 2mm line. The bands in the short answer are our own, built from the chains we sell and the weights on their listings, and every number here is nominal — at least one chain manufacturer prints "all sizes are approximate" on its own size chart. All of these chains sit in our biker necklace collection.
Chain thickness drawn to one scale (4 px per mm)
Each bar keeps the true ratio between widths: the 18mm band is nine times the 2mm line. Screen size changes the absolute size, not the ratio. The photos in this article are illustrative; these bars are the scale reference.
| Width | Chain we stock | Listed weight | Takes a pendant? |
|---|---|---|---|
| 2mm | Curb, cable, Figaro, anchor | About 5 g (cable) | Yes — slim enough for most bails |
| 3mm | Byzantine; ball chain (bead diameter) | 33 g (Byzantine) | Yes — the ball chain's end ring needs about 4mm of clearance |
| 3.5mm | Wheat (Spiga) | About 19 g at 20" | Yes — measure the bail against the end caps and clasp |
| 5mm | Byzantine | About 70 g | Yes — our widest Byzantine that still takes a bail |
| 6mm | Oval rolo | 50 g | Yes — threads most bails |
| 7mm | Byzantine | About 153 g | No — the end caps block standard bails |
| 8mm | Byzantine | 210 g | No — built to wear on its own |
| 18mm | Cuban link, 7mm deep | 315 g | Not listed for pendants — box clasp with safety latch |
Weights are the figures on our listings. Most don't state a length, and weight rises with it: a 28-inch chain carries roughly half again the metal of the same chain at 18 inches. Our 4mm Byzantine and 10mm Cuban are sold out as of October 2026, so they have no row here; a 4mm chain would sit between the 3.5mm and 5mm bars.
Why Does the Same Width Look Different on Different Chains?
Width is measured from the outside of the widest link. The US jewelry-supply house Rio Grande prints that convention in its chain buying guide. The number tells you how wide the chain is, not how deep the links are or how much silver fills the space between them.
The weave decides the rest. Rio Grande describes Byzantine chain as a repeating pattern of interlinked jump-ring pairs, wheat chain as figure-eight links closely interconnected into a braided look with an almost square profile, and curb chain as cable links twisted so they lie flat. Denser weaves tend to read as a solid line; open links such as cable or rolo let more skin show through. Our comparison of 13 men's chain types goes deeper into how each one is built.
Ball chain plays by a different rule: its size is the diameter of each bead, which is how ball-chain makers list it. A 3mm ball chain and a 3mm Byzantine share a label and very little else.
Depth is the dimension listings rarely mention. Our 18mm Cuban link chain is 18mm wide and 7mm deep front to back, and that depth is a big part of why it's listed at 315 grams. The Cuban link chain guide has the width-to-weight numbers for that one style.
3mm vs 5mm Chain: Which Width Should You Get?
If you're wondering what size chain you should get, the answer usually follows what the chain is for. In our store analytics for the 12 months to September 2026, about seven in ten of the plain sterling chains customers bought were 3.5mm or narrower.
Choose 3mm or 3.5mm when the chain's main job is carrying a pendant. Our 3mm Byzantine chain threads standard bails and is listed at 33 grams; the 3.5mm wheat chain's listing suggests small to medium pendants under about 30 g.
Choose 5mm when the chain is the piece. At 5mm the Byzantine weave becomes the focal point, and at about 70 grams it has real weight on the neck. It's also the widest Byzantine we sell that still takes a bail through its end cap.
Split the difference with a 6mm oval rolo. It is listed at 50 grams, lighter than our 5mm Byzantine, and it still threads most bails.
Check the Bail Before You Pick the Width
A pendant slides on over one end of the chain, so whatever goes through the bail first has to clear it: the end ring, the end cap or the clasp. Rio Grande's guide makes the same point about the end ring. On our woven chains the end fittings are the tight point. The wheat listing tells you to measure the bail against the end caps and clasp, not the braid, and the end caps on our 7mm and 8mm Byzantine block standard bails completely.
Measure the bail opening
Measure the hole inside the bail in millimeters, not its outside edge. A digital caliper is best; a ruler held across the opening gets you close.
Find the widest part of the chain end
That is the end cap, end ring or clasp, whichever is widest, and on woven chains it is often wider than the chain body. Our listings say which chains have this problem.
Compare, then choose
If the bail opening is smaller than that end fitting, pick a narrower chain or a pendant with a larger bail. Forcing it can scratch both pieces.
Grams Say More Than Millimeters
Read the weight next to the width. The FTC's Jewelry Guides (16 CFR 23.5) treat calling a piece "sterling" as misleading unless it is at least 925/1,000ths pure silver, so on a solid sterling chain most of the listed grams are silver. Our listings give about 5 grams for a 2mm cable chain, 70 for the 5mm Byzantine, 210 for the 8mm and 315 for the 18mm Cuban chain necklace.
Compare weights at the same length where a listing gives one. And if two chains share a width but one weighs a fraction of the other, look at the weave before you look at the price tag.
How Width and Length Work Together
A wider chain carries more visual weight at the same length, so the two choices pull on each other. Our 18mm Cuban starts at 20 inches rather than 18, and our 7mm Byzantine listing describes it sitting proud above a crew-neck collar. Pick the length that sits where you want it, then use the chart to set the width.
Quick picks
Pendant every day: 2–3.5mm curb, Byzantine or wheat. Chain worn alone but easy to live with: 5–6mm Byzantine or rolo. A statement chain with no pendant: 7–8mm Byzantine. Maximum presence: the 18mm Cuban. Most of these also sit in our sterling silver necklace collection.