How to measure your ring size at home (without a ring sizer)

Rings are the only thing we sell where being one size out makes the piece unwearable. A chain that is a bit long still works. A ring that is a bit tight comes off once, gets stuck, and lives in a drawer.

The good news is that measuring at home is accurate enough if you do it properly. Here are three methods, in order of how much we trust them.

Method 1: measure a ring that already fits

This is by far the most reliable, because it removes the guesswork about how tight is right.

1. 1Pick a ring you wear on the finger you are buying for. Not a ring from a different finger.
2. 2Lay it on a ruler and measure the inside edge to inside edge, straight across the widest point.
3. 3That number in millimetres is your inner diameter. Match it in the chart below.
4. 4Measure twice. A half-millimetre error is a full size.

Method 2: a strip of paper

1. 1Cut a strip about 1 cm wide and 10 cm long. Paper, not string — string stretches and that is where this method usually fails.
2. 2Wrap it snugly around the base of the finger. Snug, not tight: you should feel contact all the way round with no pinching.
3. 3Mark where the strip overlaps, with a pen, on the strip itself.
4. 4Slide it off, flatten it, and measure from the end to the mark in millimetres. That is your circumference.
5. 5Check it against the chart. If it lands between two sizes, take the larger one.

Before you trust the number: pull the strip up over your knuckle while it is still wrapped. If it will not pass, the measurement is too small no matter how good it feels at the base. Knuckle, then base — the ring has to clear both.

Method 3: a printable sizer

Printed ring sizers work, with one caveat that ruins most of them: printer scaling. Set your print dialogue to 100% or “actual size”, never “fit to page”, then check the printed ruler against a real one before you use it. If it is off by even two millimetres, throw it away and use the paper strip.

Conversion chart

The two timing mistakes

Fingers change size through the day by as much as half a size, and almost everyone measures at the wrong moment.

• Do not measure first thing in the morning. Fingers are at their smallest after a night's sleep, and a ring sized then will be tight by evening.
• Do not measure when you are cold, straight after exercise, or after a salty meal. Cold shrinks, heat and salt swell.
• Do measure late afternoon or early evening, at a normal room temperature, when your hands feel ordinary.
• Measure the same finger three times on different days if it is an important piece. Take the average.

Sizing a ring as a surprise gift

Borrow a ring she already wears and measure it with method one. Failing that: press one of her rings into a bar of soap or a piece of soft clay and measure the impression. If you have nothing at all, US 6 to 7 is the most-ordered range for women and US 9 to 10 for men — buy in that range, keep the receipt, and plan on an exchange.

A ring should take a little effort to get over the knuckle and then sit still. If it spins freely it is too big; if it goes on easily and will not come off, it is too small.