Tennis chains don't wear like Cuban links. A Cuban chain can run long and heavy and still read as "a chain." A tennis chain is a fixed row of set stones, so if the length or width is off, it doesn't just sag strangely, it stops looking like the piece you meant to buy.
Get the two numbers right and a piece like the Simulated Diamond Tennis Chain sits flush against your collarbone and catches light with every step. Saphir builds it on 316L stainless steel with 18K gold PVD plating, so it's waterproof and tarnish-resistant no matter how often you wear it, and every order ships with a free chain.
The short answer
For most men, 18 to 20 inches is the length that works worn alone, sitting at or just below the collarbone. Width is a separate decision. A slimmer tennis chain reads as subtle enough for daily wear under a collar. A 5mm build, like Saphir's, is wide enough to register as a tennis chain from across a room instead of just a thin sparkle.
Why length changes the whole read here
A Cuban or rope chain can sit anywhere from 18 to 24 inches and still look intentional, since the interest is in the links themselves and where they land is secondary. A tennis chain is different. It's a fixed line of stones that follows the curve of your collarbone, so a couple inches too long and it hangs into your chest instead of framing your neck. A couple inches too short and it sits high and tight, closer to a choker than a chain. There's no forgiving middle ground the way there is with a chain built from repeating links.
18 inches vs 20 inches
18 inches sits close to the base of the neck, which shows the most under a crew neck or open collar. 20 inches drops slightly lower, closer to where a collarbone actually sits on a taller or broader frame. Neither one is more correct. It comes down to your neck size and how much you want visible above a shirt. If you're between the two, 20 inches is the safer default: a chain that's a touch long still drapes fine, while one that's a touch short can pull tight the moment you turn your head.
How to check your length before you order
Wrap a soft tape measure or a piece of string around the base of your neck where you want the chain to sit, then add roughly an inch and a half for drape. A chain measured tight to the skin looks pinched once it's actually hanging. Land at 17 inches around your neck, and 18 to 19 inches of chain is usually the right call.
The mistake most sizing charts cause
A generic chart that says "20 inches fits most men" is guessing at your neck, not measuring it. Two guys can both wear a size large shirt and still need different chain lengths, since neck circumference and shoulder width don't move together the way a chart assumes. Measure your own neck once and you never have to think about it again for any chain you buy after this one.
Why width is the number people skip
Most guys size a tennis chain by length and never think about width until it's already on. Width decides whether the piece reads as delicate or as a statement. A thin build disappears against a busy shirt. Saphir's tennis chain runs 5mm, wide enough that the stones read as a continuous line of light instead of individual sparkle points, which is what makes a tennis chain look expensive instead of just shiny.
Wearing it with other chains
If you're layering, put the tennis chain on top, closest to your collar, at the shortest length in the stack. It's the piece meant to draw the eye first, and a longer chain underneath, a Cuban link or a Rope Chain, gives it somewhere to sit without the two pieces tangling every time you move.
Where Saphir comes in
The Simulated Diamond Tennis Chain is set with 5A cubic zirconia stones on a 316L stainless steel base with 18K gold PVD, built to be worn in the shower and the gym instead of saved for a night out. It's hypoallergenic, backed by Saphir's Lifetime Warranty, and comes with a free chain included, so you can start layering the day it arrives. Use BLACKFRIDAY10 for 10% off your order.
For how it compares to a Cuban build, see our Cuban link thickness guide.
Length gets a chain to hang right. Width is what makes people actually notice it. Get both, and you stop having to explain which one it is.