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Ring size guide

We'll help you find the perfect fit.

Shop all rings
Ring size guide.

How to measure ring size

Trying a ring on in person will always be the ultimate test to find a comfortable size, but you can get a good idea of sizing using either of these methods:

A woman measuring her ring size with a ring sizer tool.

Measure your finger...

Fingers can change size a little throughout the day, so you'll want to try and measure them at their biggest. To do this, take the measurement in the evening and make sure your fingers aren't cold.

  1. Decide which finger the ring will be worn on and grab a length of string, a felt tip pen and a ruler.
  2. Take the string and wrap it around the base of your finger. Make sure it's snug but not too tight - you're aiming to replicate a ring fitting comfortably. 
  3. Using the pen, make a mark where the string crosses over.
  4. Use the ruler to measure the marked length of string in mm.
  5. You now have the circumference of your finger. Find your measurement on our ring size conversion chart to get your approximate ring size.
A man trying on a gold wedding band.

...or use an existing ring

If you already have a ring that fits comfortably on the finger that you want to wear your new ring on, simply buy the same size.

Not sure what size the ring is? Here's how to find out:

  1. If you can access a printer, print a copy of our ring size PDF (we'll open this in a new tab for you) . Follow the instructions on the PDF to find out what size it is.
  2. Don't have access to a printer? Grab a ruler and measure the diameter of the ring (its widest part) in mm.
  3. Find the diameter on our ring size conversion chart to get the approximate ring size.

Ring size conversion

As is standard across most jewellers, we specify ring size with an alphabetical letter. Most of our range is available in sizes H through to V, although some rings may only be available in the most popular sizes. If you don't know what letter you need, you can find out below using the circumference of your finger or the diameter of an existing ring that fits.

Ring diameter: 14.9mm

Finger circumference: 46.8mm

Size H

Ring diameter: 15.3mm

Finger circumference: 48mm

Size I

Ring diameter: 15.5mm

Finger circumference: 48.7mm

Size J

Ring diameter: 15.9mm

Finger circumference: 50mm

Size K

Ring diameter: 16.3mm

Finger circumference: 51.2mm

Size L

Ring diameter: 16.7mm

Finger circumference: 52.5mm

Size M

Ring diameter: 17.1mm

Finger circumference: 53.8mm

Size N

Ring diameter: 17.5mm

Finger circumference: 55.1mm

Size O

Ring diameter: 17.9mm

Finger circumference: 56.3mm

Size P

Ring diameter: 18.3mm

Finger circumference: 57.6mm

Size Q

Ring diameter: 18.8mm

Finger circumference: 58.9mm

Size R

Ring diameter: 19.2mm

Finger circumference: 60.2mm

Size S

Ring diameter: 19.6mm

Finger circumference: 61.4mm

Size T

Ring diameter: 20mm

Finger circumference: 62.7mm

Size U

Ring diameter: 20.4mm

Finger circumference: 64mm

Size V

Buying for someone else?

A man proposing to his girlfriend with a ring in a box.

Here's how to find out their ring size

This can be tricky if you're surprising them with a ring, but there's a couple of methods you can try:

  1. Get help: ask their close friends or family. They may know their size if they've bought a ring for them in the past, or if not they may be able to find out a bit more subtly than you could.
  2. Borrow a ring: If you can get hold of a ring that they already own and wear on the finger you're buying for, you can measure the diameter and find their size using our ring size conversion guide.

If it doesn't fit

Even if you have carefully tried to work out what size ring you need, there's still a chance the ring won't fit exactly as you want it to. If this happens, don't panic. You can easily take it back into any Argos store within 30 days of purchase and exchange the ring for a different size. 

Find your nearest store here.

For diamond rings, they will need to be sent off for verification with the original size tag on it before they can be exchanged, so you would not be able to get the new ring straight away.

More advice

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