How to Find Your Ring Size at Home — 5 Methods

Why Ring Size Matters for Lab-Grown Engagement Rings

Most custom lab-grown engagement rings can be resized after delivery. But the resizing window matters:

• Resizing up 1-2 sizes: Usually manageable. The jeweller adds metal.
• Resizing down 1-2 sizes: Also manageable. The jeweller removes metal and re-solders.
• Resizing by 3+ sizes: Can stress the setting, especially pave or eternity bands where accent stones are set around the full circumference.
• Resizing a full-pave eternity band: Very difficult without significant cost - stones must be removed, the band resized, stones reset.

For solitaires and most custom designs, 1-2 sizes of error is easily corrected. For eternity bands and full-pave designs, accuracy matters more.

Method 1: String or Paper Strip Wrap

What you need: A thin strip of paper or string, a pen, a ruler

How to do it:

1. Cut a thin strip of paper (2-4mm wide) or cut a piece of string about 15cm long
2. Wrap snugly around the base of the finger where the ring will sit
3. Mark where the end meets the strip/string
4. Measure the length from the start to the mark in millimetres
5. Use a standard ring size chart to convert circumference to ring size (see table below)

Tips:

• Measure at the end of the day - fingers are slightly larger in the afternoon/evening due to temperature and activity
• Measure the specific finger: dominant hand fingers are typically slightly larger
• Don't wrap too tightly - the ring needs to slide over the knuckle

Accuracy: Moderate. The paper or string can stretch slightly, and the wrapping pressure affects the measurement. Use this as a starting estimate and confirm with another method if possible.

Method 2: Measure an Existing Ring

If your partner has a ring they currently wear on the same finger, you can measure its diameter.

What you need: A ruler or calipers (digital calipers are ideal, ~C$15 at any hardware store), the existing ring

How to do it:

1. Place the ring on a flat surface
2. Measure the inside diameter (the open space inside the ring, not the outer edge of the metal) in millimetres
3. Use the size chart below to convert diameter to ring size

Tips:

• Measure the inside diameter, not the outside
• If the ring is a different finger (index vs ring finger), the size won't apply - fingers vary significantly in size

Accuracy: High, if you're measuring the correct finger. This is the most reliable non-professional method.

Method 3: Printable Ring Size Gauge

Several jewellery websites and Lux Jewels' consultation preparation guide include a printable ring size gauge - a printed page with circles of known diameter.

How to do it:

1. Print the gauge at exactly 100% scale (not "fit to page") - verify by measuring the printed 1-inch reference box
2. Place your partner's ring over each circle until you find the one that matches the inside circumference

Tips:

• Verify print scale before trusting the result. A printer printing at 97% instead of 100% will make every size read slightly small.
• This method works best with a reference ring from the same finger

Accuracy: Moderate-high if print scale is verified.

Method 4: Purchased Ring Sizer Tool

Ring sizer tools are inexpensive (C$5-C$20) and available at jewellery supply stores, Amazon Canada, or requested from us before your consultation.

A ring sizer is a set of metal or plastic rings in standard Canadian/US sizes (typically 3-13 in half sizes) that you can try on the finger.

How to use:

1. Try each sizer ring over the knuckle - the ring should slide over the knuckle and fit snugly (but not uncomfortably) at the base
2. If between sizes, size up

Accuracy: High - the most accurate non-professional method. Simulates the actual ring-wearing experience.

Method 5: Professional Measurement at a Local Jeweller

Any local jeweller will measure ring size free of charge in under 2 minutes. No purchase required.

What to do:

1. Go to any jewellery store
2. Ask for a ring size measurement (they'll have ring sizers)
3. Ask them to measure the specific finger where the engagement ring will be worn
4. Note the result in both US/Canadian size and millimetres (ask for both)

Accuracy: Highest of all methods.

Ring Size Conversion Table (Canadian/US to mm)

Canadian and US ring sizes use the same scale.

Most Canadian women's ring fingers fall in the size 5-7 range (16.5-17.3mm diameter). Most men's range falls in the 9-11 range.

The Knuckle Problem

The ring needs to slide over the knuckle to reach the base of the finger. If your partner has large knuckles relative to their base finger width, they may need to size up slightly to accommodate the knuckle - which means the ring may feel slightly loose when sitting at rest at the base.

For this situation, there are a few solutions:

• Comfort-fit band: Slightly rounded interior that slides over knuckles more easily
• Sizing beads: Small metal beads welded inside the band that make the ring fit more snugly at the base while the larger opening still passes over the knuckle

Let us know during the consultation if this applies and we'll factor it into the design.

Guessing Your Partner's Size (Proposal Rings)

If you're buying a surprise ring:

1. Borrow an existing ring from the same finger - the inside diameter method (Method 2) works well
2. Ask their friends or family - someone close often knows
3. Default to size 6 - the statistical average for Canadian women's ring fingers
4. Size up rather than down - resizing up (adding metal) is slightly simpler than resizing down (removing metal and re-soldering)
5. I've helped hundreds of clients get the sizing right for surprise proposals since founding Lux Jewels in 2007. Book a free consultation and I'll walk you through exactly what to do.