How do you measure your ring size at home?
Wrap a strip of paper or string around the base of the finger, mark where it meets, measure the length in millimetres, then divide by 3.14 for the diameter. Measure at the end of the day, on the exact finger, and check the knuckle as well as the base.
By SIAFRA
Take a strip of paper or a piece of string, wrap it around the base of the finger, and mark where the ends meet. Measure that length in millimetres: it is the circumference. Divide it by 3.14 for the inside diameter. Both numbers appear on every ring size chart.
Three things decide whether the answer is right, and all three are easy to get wrong.
Measure at the end of the day
Fingers change through the day. As Blue Nile puts it: “Finger size can vary with temperature, time of day, and even which hand you use most. It’s better to take your measurement at the end of the day when your fingers are warm and slightly larger.” A ring sized from a cold morning finger is a ring that will not come off in August.
Measure the exact finger
The same finger on your dominant hand is usually larger than on the other, and the ring finger and index finger are rarely the same. Measure the finger the ring is actually for, two or three times, and take the reading that repeats.
Check the knuckle
This is the one that ruins otherwise careful measurements. A ring has to pass the knuckle and then sit on a narrower base. Blue Nile’s instruction: “If your knuckle is wider than the base of your finger, measure both and choose a size in between for the best fit.”
The chart
| US size | Inside diameter | Inside circumference |
|---|---|---|
| 5 | 15.7mm | 49.3mm |
| 6 | 16.5mm | 51.9mm |
| 7 | 17.3mm | 54.4mm |
| 8 | 18.1mm | 57.0mm |
| 9 | 18.9mm | 59.5mm |
| 10 | 19.8mm | 62.1mm |
Values as published by RingSize, which also carries the quarter and half sizes. If your measurement falls between two sizes, size up: a ring that will not pass the knuckle is unwearable, while one slightly loose can be sized or worn on another finger.
Buying a ring as a gift
Do not guess. A guessed ring size is the most common jewelry return in January. Either borrow a ring she already wears on that finger and measure its inside diameter, or buy something that needs no size at all. Earrings need none, and an open cuff adjusts across a range of wrists.
More on that in is gold-plated jewelry a good gift.
What SIAFRA publishes
The size run is confirmed with the first production batch and published before orders open. The waitlist asks for a ring size as an optional field, which is how the run is planned: sizes nobody asked for do not get made.
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