Ring Size Guide: Find Your Perfect Fit
4 min read · By the Regal Jewels team
Simple at-home methods to measure your ring size, US size conversions, and tips for surprise proposals.
Measure with a ring you own
The most accurate home method is measuring the inside diameter of a ring that already fits the intended finger. Place it on a ruler and measure edge to edge inside the band in millimeters. For example, about 16.5mm corresponds to US size 6, 17.3mm to size 7, and 18.1mm to size 8.
The string method
Wrap a strip of paper or non-stretch string snugly around the base of the finger, mark where it overlaps, and measure the length in millimeters — that is the circumference. Divide by 3.14 to estimate the diameter. Measure at the end of the day when fingers are warm, since cold fingers shrink slightly.
Fit tips
A correctly sized ring slides on smoothly and resists slightly over the knuckle when removed. Wide bands fit tighter, so consider going up a quarter to half size for bands over 6mm. If you are between sizes, size up — rings can usually be resized down more easily.
Buying a surprise ring?
Borrow a ring your partner wears on the correct finger and trace its inside circle on paper, or ask us — at our Devon Avenue store we can size any ring on the spot, and most of our rings can be adjusted after the proposal.
Still have questions?
Our jewelers answer questions every day — in store on Devon Avenue, or on WhatsApp.