Getting the size right

A finger is not a fixed size. It is measurably larger at the end of a warm day, after exercise and after salt; smaller first thing in the morning and in cold weather. The swing is commonly half a UK size and can be a full size.

So: measure in the late afternoon or evening, at normal room temperature, and measure on more than one day. If two readings disagree, take the larger one — a ring slightly loose can usually be brought in, a ring too tight is the harder problem, and on a full eternity band neither is possible.

The only method that measures the finger in the conditions the ring will actually live in. Wear the sizer for a full day. It should go over the knuckle with a small amount of resistance and sit without spinning freely.

The reusable plastic sizer is GBP £5 and the adjustable band covers the whole UK range. The steel set at GBP £15 is more accurate because each band is a fixed circumference, and it is the better choice if you are measuring someone else’s hand. Either cost comes off your ring order in full — one deduction, on the order that follows.

Take a ring that fits the correct finger, lay it over the printed circles below, and find the circle whose outline sits just inside the inner edge of the band. If it falls between two, go up.

The circles are drawn at actual size. Print the sheet at 100 percent with any “fit to page” or “shrink to fit” option switched off, then check the calibration bar with a ruler before you trust anything on the page. A sheet printed at 94 percent will send you a size and a half out.

One point on this method: a ring worn on a different finger, or a wide band compared against a narrow one, will mislead you. Wide bands need a slightly larger size than narrow ones at the same finger.

Wrap a strip of paper or a length of non-stretch thread around the base of the finger, mark where it overlaps, lay it flat and measure the length in millimetres. That figure is the circumference — find it in the table below.

The strip has to pass over the knuckle, so check it will before you settle on the reading. This is the least reliable of the three methods and the one most likely to read small.

The British scale starts at 12.04 mm of internal diameter for size A and rises 0.4 mm per letter, with half sizes at the midpoints. Both columns below are calculated from that rule rather than copied from a chart, so the letter and the millimetre figure cannot disagree.

Sizes F to Z are held in stock. Outside that range is bench work, which we do not offer.

We do not claim that any ring is guaranteed to fit. Nobody selling remotely can honestly say that. What we can do is publish the millimetres, sell you a sizer for the price of a coffee, take the cost of it back off the ring, and state on every product page exactly how far that particular ring can be moved afterwards — including the rings that cannot be moved at all.