How do I get the ring size right if she has knobby knuckles?

A ring that clears the knuckle but spins at the base is the most common ring sizing mistake I see. If she has knobby knuckles, the key to getting the ring size right is to measure twice and then build for the larger number. The base and the knuckle are two different measurements, and any jeweler who only takes one of them is guessing.

Measure the knuckle and the base separately

Most ring gauges measure the base of the finger, not the knuckle. For most people, that's fine. For someone with prominent knuckles, the base measurement alone will produce a ring that won't go over the joint without a fight. Have her try on a set of wide-band sizers, the kind with a smooth interior. She slides them over the knuckle, then you note where the fit feels snug but not painful. That number is the working size. Then measure the base with the same gauge and write both down. The difference between the two numbers is what tells me what to do next.

Last spring, a client named Daniel walked in with an engagement ring he'd bought online as a size 8, sized by a string. His partner's base was a 6.5, but her knuckle was a 7.75, so the ring cleared the joint in summer, then got stuck during a cold snap in November. That's a size and a quarter of travel. We sized it to 7.75 and added beads, but it still spun at the base when her hands were cold. She ended up with a hinged shank. That's the reality with knobby knuckles: no single static size solves the problem year-round.

The fixes that actually work

Once you know the spread, the ring gets sized to the knuckle. Then we solve the base. If the difference is small, under about three-quarters of a size, a pair of sizing beads soldered inside the bottom of the shank is usually enough. These are two small metal dots at the 4 and 7 o'clock positions. The finger tissue compresses around them, so the ring sits straight without spinning, but the knuckle still passes over because the beads sit below the joint line.

If the gap is bigger, I prefer a hinged shank. A small hidden hinge on one side and a catch on the other. The ring opens to slip over the knuckle, then closes to a tighter fit at the base. It costs more, roughly $180 to $350 extra on a custom ring, and not every local jeweler does it well. Ask to see at least two examples of their hinged work before you commit.

• Sizing beads for small gaps, under about 0.75 sizes.
• A spring bar or euro shank for hands that swell and shrink.
• A hinged shank for gaps over one full size.
• A wider band, which distributes pressure and makes a slightly loose base less noticeable.

Don't buy a tungsten or titanium ring for this finger. They cannot be resized or hinged. If the knuckle changes with weather, you're stuck. Same goes for full pavé bands that wrap all the way around the shank. Any later sizing will pop stones out.

If it's a surprise ring, plan for a second visit

If you're doing this as a surprise, a borrowed ring is only half the story. It tells you the base size, not the knuckle. You need both. The most reliable approach is to buy a simple band that can be modified after the proposal, then bring her in for the real fit. Don't let a salesperson talk you into a tension setting or an eternity band for a hand with prominent knuckles. Those choices make a tricky size into an expensive repair.

Bring both numbers to your jeweler. If they don't ask for both, leave.