How To Measure Ring Size

Accurately measuring your ring size is the first step when ordering a ring online. Because of the tricky nature of ring sizing, we offer one free remake/resize on all of our rings (you can see our resizing policies here). 

Ring Sizing Made Easy

Get a free sizer set with the purchase of any ring.

Ring Sizers

HOW TO MEASURE YOUR RING SIZE AT A LOCAL JEWELERY STORE
(not necessary if you have used our sizing set).

It’s common to be sized a little differently from one jeweler to the next, so it’s best to be sized by more than one jeweler. Try to have at least two jewelers agree on your size before proceeding with an online ring order. Otherwise, you may be ordering a ring that doesn’t quite fit.

RING WIDTH

Wider rings fit tighter than narrow rings. For example, if a size 6 ring that is 3mm wide fits you perfectly, then a size 6 that is 7mm wide may feel a little too snug. The difference in fit between wide and narrow bands isn’t a lot – usually in the range of 1/4 to 1/2 size.

Depending on how you like your ring to fit, this could mean the difference between just perfect and too tight to wear. So, for better accuracy it is always best to be sized with a sizer/ring that is the same width as the ring you intend to order.

comfort fit vs standard fit

TYPE OF FIT

Another thing to consider when being sized by a jeweler is the ring’s fit. There are two types of fit that are important when being sized: standard fit (a.k.a. pipe fit) and comfort fit.

Standard fit rings are flat on the interior of the band, while comfort fits rings are dome-shaped on the interior. What this means in practical terms is that a comfort fit ring will feel slightly larger than a standard fit ring of the same size.

There isn’t much of a difference in terms of sizing between comfort fit and pipe fit bands that are narrower in width. The difference in size can be felt more with wider bands. Our wider rings are made with a partial comfort fit, which basically means that they have deeply rounded inner edges. They fit similarly to a comfort fit band, but they aren’t that far off from a pipe fit either, so feel free to be sized with either type.

RING SIZING TECHNIQUES

Jewelers generally use one of two techniques to size a ring. They either use a graduated ring mandrel, or they measure the inside diameter of a ring using digital calipers. Ring mandrels can be accurate if manufactured correctly, but unfortunately, there are many different types and brands floating around, quite a few of which aren’t very accurate.

If you already have a ring that fits you or the person you are buying the ring for, the most accurate way to get its size is to measure its inside diameter with digital calipers. This is also true for ring sizers: if you are sized by a jeweler and find that a particular ring or sizer fits best while in their shop, ask them if they can measure the inside diameter of the ring/sizer for you.

SIZING CHART

There isn’t an exact standard used when sizing rings, but most jewelers around the world use similar measurements. We have posted a standard international ring sizing chart below as a reference, as well as to show the millimeter to ring size conversion that Casavir Jewelry uses. If on a mobile device scroll to the right to see all columns.

International Ring Size Chart

Inside diameter
in millimeters (mm)
Sizes:
United States,
Canada,
Mexico
Sizes:
United Kingdom,
Ireland,
Australia,
South Africa,
New Zealand
Sizes:
China,
Japan,
South America
Sizes:
Italy,
Spain,
Switzerland
14.073F44.25
14.273.25F 1/254.75
14.483.5G5.5
14.683.75G 1/266
14.884H76.75
15.094.25H 1/27.5
15.294.5I88
15.494.75J8.75
15.75J 1/299.25
15.95.25K10
16.15.5K 1/21010.5
16.315.75L11.25
16.516L 1/21111.75
16.716.25M1212.5
16.926.5M 1/21313.25
17.126.75N13.75
17.327N 1/21414.5
17.537.25O15
17.737.5O 1/21515.75
17.937.75P16.25
18.148P 1/21617
18.348.25Q17.5
18.548.5Q 1/21718.25
18.758.75R19
18.959R 1/21819.5
19.159.25S20.25
19.359.5S 1/21920.75
19.569.75T21.5
19.7610T 1/22022
19.9610.25U2122.75
20.1710.5U 1/22223.25
20.3710.75V24
20.5711V 1/22324.75
20.7811.25W25.25
20.9811.5W 1/22426
21.1811.75X 26.5
21.3912X 1/22527.25
21.5912.25Y27.75
21.7912.5Z2628.5
2212.75Z 1/229
22.2132729.75
22.413.25Z130.5
22.6113.531
22.8113.75Z231.75
23.0114Z332.25
23.2214.2533
23.4214.5Z433.5
23.6214.7534.25
23.831534.75
24.0315.2535.5
24.2315.536.25
24.4315.7536.75
24.641637.5