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Class Ring Size Chart: MM, Inches, US, UK & EU Sizes + Free PDF


Class Ring Size Chart: Sizes in MM, Inches, US, UK & EU

A class ring size chart converts your finger measurement into a ring size. Class rings, the graduation rings made for schools and colleges, use the same US, UK and EU sizes as other rings, but their wide, heavy bands and large stones often make them fit tighter. Use the chart below to find your size, then read the fit tips for men’s and women’s class rings.

Quick answer: a US size 7 class ring has an inner diameter of 17.32 mm (0.682 in) and an inner circumference of 54.4 mm, which is UK N½ and EU 54. Measure your finger in mm, match it to the chart, and go up a quarter to a half size if the band is wide and heavy.
Get the printable class ring size chartFree A4 PDF with a 100% print-scale check. No sign-up needed.

Download the Class Ring Size Chart PDF

How Class Rings Are Sized

A class ring is a graduation ring, usually from a high school or college, with a stone or emblem, the school name or crest, and the graduation year. It is sized exactly like any other ring: by the inside diameter or circumference of the band. The ISO 8653 standard defines ring size by inside circumference in millimetres; see the ring size overview for background.

What makes class rings different is the fit. Many have a broad face, a large stone and a thick shank, so a ring that matches your measurement on paper can still feel snug. Makers such as school ring companies usually publish their own sizing guides or size kits, so check the one for your order.

Class Ring Size Conversion Chart (MM, Inches, US, UK, EU)

Inner diameter is the width across the inside of the band. Inner circumference is the distance around it. Highlighted rows are common reference points.

Class ring size conversion chart, US sizes 3 to 13
Ring size (US) Inner diameter (mm) Inner diameter (in) Inner circumference (mm) US UK EU
3 14.07 0.554 44.2 3 F 44
3.5 14.47 0.570 45.5 3.5 G 45
4 14.88 0.586 46.8 4 H 47
4.5 15.29 0.602 48.0 4.5 I 48
5 15.69 0.618 49.3 5 J½ 49
5.5 16.10 0.634 50.6 5.5 K½ 51
6 16.51 0.650 51.9 6 L½ 52
6.5 16.91 0.666 53.1 6.5 M½ 53
7 17.32 0.682 54.4 7 N½ 54
7.5 17.73 0.698 55.7 7.5 O½ 56
8 18.13 0.714 57.0 8 P½ 57
8.5 18.54 0.730 58.2 8.5 Q½ 58
9 18.95 0.746 59.5 9 R½ 60
9.5 19.35 0.762 60.8 9.5 S½ 61
10 19.76 0.778 62.1 10 T½ 62
10.5 20.16 0.794 63.3 10.5 U½ 63
11 20.57 0.810 64.6 11 V½ 65
11.5 20.98 0.826 65.9 11.5 W½ 66
12 21.38 0.842 67.2 12 X½ 67
12.5 21.79 0.858 68.5 12.5 Z 68
13 22.20 0.874 69.7 13 Z½ 70

Formulas used: circumference = π × diameter; inches = mm ÷ 25.4; EU size = inner circumference in mm, rounded. UK letters are matched to the nearest published inner diameter. Sizes vary slightly by brand.

Women’s Class Ring Sizes

Women’s class rings are often lighter and narrower than men’s styles. Ring-finger sizes commonly fall between about US 5 and US 8, though every hand is different. See also the women’s ring size chart.

Women’s class ring sizes: US 5 to 8
Ring size (US) Inner diameter (mm) Inner diameter (in) Inner circumference (mm) US UK EU
5 15.69 0.618 49.3 5 J½ 49
5.5 16.10 0.634 50.6 5.5 K½ 51
6 16.51 0.650 51.9 6 L½ 52
6.5 16.91 0.666 53.1 6.5 M½ 53
7 17.32 0.682 54.4 7 N½ 54
7.5 17.73 0.698 55.7 7.5 O½ 56
8 18.13 0.714 57.0 8 P½ 57

Men’s Class Ring Sizes

Men’s class rings are commonly bought in sizes from about US 8 to US 12 for the ring finger. Larger faces and thicker shanks fit more snugly, so consider going up a quarter to a half size. See also the men’s ring size chart.

Men’s class ring sizes: US 8 to 12
Ring size (US) Inner diameter (mm) Inner diameter (in) Inner circumference (mm) US UK EU
8 18.13 0.714 57.0 8 P½ 57
8.5 18.54 0.730 58.2 8.5 Q½ 58
9 18.95 0.746 59.5 9 R½ 60
9.5 19.35 0.762 60.8 9.5 S½ 61
10 19.76 0.778 62.1 10 T½ 62
10.5 20.16 0.794 63.3 10.5 U½ 63
11 20.57 0.810 64.6 11 V½ 65
11.5 20.98 0.826 65.9 11.5 W½ 66
12 21.38 0.842 67.2 12 X½ 67

Wide Bands and Large Stones: Should You Size Up?

Slim band versus wide class ring bandOn the left a slim band sits lightly on a finger; on the right a wide, heavy class ring band with a large stone covers more of the finger and fits tighter, so a quarter to half size up may be needed. Slim bandLight contactTrue size usually fits Wide class ringMore contact, feels tighterConsider a quarter to half up
A wide class ring with a large stone touches more of the finger, so it often feels tighter than a slim band in the same size.

A wider band has more contact with the skin and is harder to slide over the knuckle. If you are between sizes, or the class ring band is wide or heavy, many people choose a quarter to a half size larger. Always check the maker’s size notes and return or exchange policy, because shank shape and weight differ by style.

Class ring fit by style
Style How it compares Fit tip
Slim or women’s style Lighter band, less contact Your measured size usually fits
Wide or heavy style More contact, often feels tighter Consider a quarter to half size up
Large stone or tall face Can press on neighbouring fingers Check comfort when the hand is flat and gripping

Which Finger Do You Wear a Class Ring On?

Many graduates wear a class ring on the ring finger of the right hand, which keeps the left ring finger free for a wedding ring, but there is no rule. Others wear it on the left hand, the index finger or the pinky. Fingers on the same hand can differ by a size or more, so measure the exact finger you will wear it on.

How to Measure Class Ring Size in MM and Inches

Millimetres are the most accurate unit. Convert to inches by dividing by 25.4. Our how to measure your ring size guide and the ring size calculator cover more methods.

Measure an Existing Ring

Measuring the inner diameter of a class ringA class ring with a large stone on the face seen from above, with a horizontal line across the inside edge to edge labelled inner diameter. Inner diameter 1. Measure inside edgeto inside edge, not thestone, face or outer band. 2. Read it in mm.Inches = mm ÷ 25.4Example: 16.51 mm = 0.650 in
Measure the inside of the band edge to edge, away from the stone or face.
  1. Choose a ring that fits the same finger comfortably.
  2. Lay it flat and measure the inside width at its widest point, in mm.
  3. Find the nearest value in the “Inner diameter (mm)” column.
  4. Multiply the diameter by 3.1416 to check the circumference.

Measure Finger Circumference with a Paper Strip

Measuring finger circumference with a paper stripA paper strip wrapped around a finger with a pen mark where the end overlaps, then laid flat against a ruler. 1. Wrap and mark 0mmmm Length 0 to mark = circumference 2. Lay flat and measure in mm
Wrap, mark, then measure the strip against a ruler.
  1. Cut a strip of paper about 10 mm wide and 150 mm long.
  2. Wrap it around the base of the finger you will wear the class ring on and mark where it overlaps.
  3. Lay the strip flat and measure from the end to the mark in mm.
  4. Match the result to the “Inner circumference (mm)” column. Use string or a tape measure the same way.
Tip: measure at the end of the day when fingers are warm, and repeat three times. If your knuckle is larger than the base of your finger, choose a size that passes the knuckle.
Print the chart and check your sizeFree A4 PDF with a 100% print-scale check. No sign-up needed.

Download the Class Ring Size Chart PDF

How to Choose the Right Class Ring Size

  • Pick the finger first. Ring finger, index finger and pinky need different sizes.
  • Use millimetres. Compare your circumference with the chart and the maker’s size guide.
  • Check the band width and stone. Wide bands and large faces feel tighter; go up a quarter to a half size if between sizes.
  • Check the knuckle. The ring must pass over it and still sit snugly.
  • Confirm the policy. Ask how the maker handles exchanges or resizing before you order.

Can Class Rings Be Resized?

Sometimes, but ask the maker or a jeweller before you order or alter one. Engraving, side designs, enamel and large stone settings can limit resizing, and large changes can distort the shape of the ring. Related guides: US ring size chart, UK ring size chart and ring size conversion chart.

Class Ring Size FAQs

What size is a class ring?

There is no single class ring size. Class rings are made in the same US, UK and EU sizes as other rings, and the size you need depends on your finger. Many men’s class rings are ordered between about US 8 and US 12, and many women’s between about US 5 and US 8, but measure your own finger.

Which finger is a class ring worn on?

Many graduates wear a class ring on the ring finger of the right hand, so it stays separate from a future wedding ring, but there is no rule. Some people wear it on the left hand, the index finger or the pinky. Size for the exact finger you will wear it on.

Do class rings fit tighter than regular rings?

They often do. Class rings tend to have a wide, heavy band and a large stone or face, which gives more contact with the finger. Many people go up a quarter to a half size if they are between sizes, but check the maker’s size notes.

How do I measure my class ring size at home?

Wrap a strip of paper around the base of the finger, mark the overlap and measure the length in millimetres. Match that circumference to the chart on this page. A ring that already fits the same finger can also be measured across the inside.

Can a class ring be resized?

Sometimes, but not always. Engraving, side designs, enamel, a large stone setting and the thickness of the band can limit how much a class ring can be resized. Ask the maker or a jeweller before you buy, and confirm the resizing policy.

Does the season affect my class ring size?

It can. Fingers often swell in heat and shrink in cold, so measure at different times of day and choose a size that is comfortable in both. If you are between sizes, ask the maker about their fit and exchange policy before ordering.

Is a women’s class ring sized differently from a men’s one?

No. They use the same size scales. The difference is in the design: women’s rings are often lighter and narrower, so they may fit closer to your measured size, while heavier men’s styles often feel tighter.

Will my class ring size change over time?

It can. Finger size can change with age, weight, pregnancy, temperature and activity. If the ring is a keepsake you plan to wear for years, measure again before ordering and keep the maker’s resizing options in mind.

Related Ring Size Guides

Download your free class ring size chartFree A4 PDF with a 100% print-scale check. No sign-up needed.

Download the Class Ring Size Chart PDF

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