There are two Cuban link chains in our case right now that weigh almost exactly the same. One is 127.6 grams. The other is 127.7 grams. A tenth of a gram apart — close enough that you'd have to look at the scale twice.
They look nothing alike. The first is 9mm wide and 22 inches long: short, thick, sits high near the collarbone. The second is 8.5mm and 26 inches: longer, visibly slimmer, hangs down on the chest. Same karat, same style, same amount of gold in the room. Completely different chain.
That pair is the whole lesson. Gram weight tells you what a chain is worth. It tells you almost nothing about what it looks like. And the number most people fixate on — the millimeter width — moves the weight far faster than anyone expects.
Width is two-dimensional, and price follows
Here's the question we get across the counter more than almost any other: why is the 12mm so much more than the 9mm? It's barely bigger.
Because width isn't a length. A chain link is a solid object with height and depth, and when a manufacturer makes it wider they make it proportionally taller and thicker too. Double the millimeters and you don't double the gold — you roughly quadruple it. Same reason a 16-inch pizza is a lot more than twice an 11-inch pizza.
That's easy to assert. Here's what it actually looks like on our own shelf. Every row below is a 10K Miami Cuban link chain currently in the store, weighed on our scale:
| Width | Length | Total weight | Grams per inch |
|---|---|---|---|
| 6mm | 26" | 65.7 g | 2.5 |
| 6.5mm | 25" | 81.9 g | 3.3 |
| 8.5mm | 26" | 127.7 g | 4.9 |
| 9mm | 22" | 127.6 g | 5.8 |
| 9.5mm | 24" | 154.2 g | 6.4 |
| 10.5mm | 28" | 209 g | 7.5 |
| 11mm | 25" | 181.2 g | 7.2 |
| 11mm | 26" | 228.4 g | 8.8 |
| 12mm | 25" | 240.6 g | 9.6 |
| 25mm | 23.5" | 817.3 g | 34.8 |
Look at the last column. That's grams per inch — total weight divided by length — and it is the only fair way to compare two chains that aren't the same size.
The 6mm carries about 2.5 grams for every inch of chain. The 12mm carries about 9.6. That's just under four times the gold for a chain that is exactly twice as wide. Check it anywhere on the list and the pattern holds: the 9mm sits at 5.8, which is about 2.3 times the 6mm figure — and 9 divided by 6, squared, is 2.25.
The number worth asking for
Two things fall out of that table that are worth carrying into any jewelry case, ours or anyone else's.
Length quietly inflates the weight. A 26-inch chain needs about 18% more gold than a 22-inch chain of identical width, purely because there's more of it. So a chain advertised as "heavier" may just be longer. Grams per inch strips that out.
The same stated width isn't the same chain. We have two 11mm Cubans on that list. One runs 7.2 grams per inch, the other 8.8 — about 21% apart, at the same advertised millimeter. Width is measured at the widest point of the link, and link profiles vary between manufacturers. The tape measure starts the conversation. The scale ends it.
Where the math stops working
The squared rule is a good mental model, not a law. Three things break it.
Very wide chains flatten out. Our 25mm piece runs 34.8 grams per inch. Pure squared math off the 6mm would predict something closer to 44. Once chains get past roughly 12 to 15mm, they're generally built flatter relative to their width — a link that stayed perfectly proportional at 25mm would be too thick to lie against your chest.
Hollow construction throws it out entirely. A hollow link is a shell. Its outside dimensions tell you nothing about how much gold is inside it, which is precisely why nobody who buys gold for a living quotes off a measurement.
Link style changes the density. Rope, Franco, figaro and mariner all pack gold differently at the same stated width. Compare Cuban to Cuban, rope to rope.
What to actually do with this
If you're shopping for a chain, pick the look first. Decide the width you want on your neck, then the length, and let the weight land where it lands — but go in expecting a real jump between sizes rather than being surprised by it at the counter. The step from 9mm to 12mm is not a small upgrade. It's most of another chain.
If you're on the other side of it — selling a chain or borrowing against one — the width is almost beside the point. Karat and gram weight are what the offer is built on. Width only matters because it's what produced the weight.
Either way: bring the chain, not a photo of it. We'll put it on the scale in front of you and you can watch the number come up.
DD Pawn Loans is at 2751 W Atlantic Blvd in Pompano Beach, serving Fort Lauderdale, Deerfield Beach, Coconut Creek and the rest of Broward County. We buy gold, sell it, and write collateral loans against it — no credit check. Call (561) 774-9292 or browse our Cuban link chains.