Ring Size Guide

Getting the size right the first time matters — especially for a bespoke piece. Here are four reliable ways to find your size from home, plus everything you need to know before ordering.

How ring sizing works

Size is measured by the inside diameter.

A ring size corresponds to the interior diameter of the band — the distance straight across the inside of the ring, measured in millimetres. The larger the diameter, the higher the size number. Simple in principle; the tricky part is measuring accurately when you don't have the ring in front of you yet.

Ring size is determined by the inside diameter of the band.

How to measure

Four ways to find your size at home.

You don't need any special tools — just a little patience and one of the methods below. We recommend trying two methods and comparing. If they match, you're confident. If they differ by half a size, go with the larger.

The string or paper strip method

Cut a thin strip of paper or use a piece of string. Wrap it snugly — not tightly — around the base of the finger you want to size. Mark where it overlaps. Measure the length in millimetres against a ruler. That measurement is your circumference — use the chart below to find your size.

Best for: measuring a finger with no existing ring to reference.

Measure an existing ring

Find a ring that already fits the correct finger well. Place it flat on a white piece of paper and trace the inside of the ring with a pencil. Measure straight across the circle you've drawn — diameter in millimetres. Match that to the chart below.

Best for: sizing a surprise proposal ring using a ring from their collection.

Use a ring sizer app

Several reliable ring sizer apps allow you to place an existing ring on your phone screen and calibrate the size against your phone's actual display dimensions. While not perfectly precise, these are a good cross-check against other methods.

Best for: a quick sanity check alongside another measurement.

Visit a local jeweller

Any local jeweller can measure your ring size in under two minutes using a professional ring mandrel and sizer set. This is the most accurate method and we recommend it for pieces with narrow band widths where a half-size error is noticeable.

Best for: maximum accuracy — especially important for wide bands.

Full size reference

US / Canadian ring size chart.

Canada and the United States use the same ring sizing system. All Stara Designs pieces are sized using US/Canadian standards.

US / CA Size	Inside Diameter (mm)	Inside Circumference (mm)	Notes
4	14.9	46.8
4.5	15.3	48.0
5	15.7	49.3
5.5	16.1	50.6
6Most common — women	16.5	51.9	Average women's size
6.5	16.9	53.1
7	17.3	54.4
7.5	17.7	55.7
8	18.1	57.0
8.5	18.5	58.3
9	18.9	59.5
9.5	19.4	60.8
10Most common — men	19.8	62.1	Average men's size
10.5	20.2	63.4
11	20.6	64.7
11.5	21.0	66.0
12	21.4	67.2
13	22.2	69.8

Relative size comparison — not to scale

15.7mm

16.5mm ★

17.3mm

18.1mm

18.9mm

19.8mm

Before you measure

Six things that affect your ring size.

Time of day

Fingers are smallest in the morning and largest in the evening. Measure mid-afternoon for the most representative size.

Temperature

Cold weather causes fingers to shrink. Warm weather causes them to swell. Measure at room temperature, not after being outside.

Dominant hand

Your dominant hand is typically half a size larger. If you're sizing for your right hand, measure that hand specifically.

Knuckle size

If your knuckle is noticeably wider than the base of your finger, size to the knuckle — the ring needs to pass over it comfortably.

Band width matters

Wider bands sit tighter on the finger. If your band is 6mm or wider, consider going up a half size from your measured size.

When in doubt

Go up, not down. It's easier to size a ring down than up — and a slightly loose ring is more comfortable than one that won't pass the knuckle.

Not sure? That's what we're here for.

If you're unsure of your size — especially for a surprise proposal — reach out before ordering. We can advise based on your specific design, band width, and finger shape. We'd rather spend five minutes helping you get it right than have you need a resize.

The Stara approach

We confirm your size before anything is made.

For every bespoke piece, we confirm your ring size as part of the design and approval process — before your piece ever enters production. This is one of the reasons we don't rush: getting the details right at the start saves everyone time, cost, and disappointment.

And if your size changes after delivery — it happens — your piece comes with one complimentary resize within the first year. See our Free Resizing Guide for full details.