Ring Sizing Guide

How to choose the correct ring size

AS29 logo with the Rings Size Guide title

Choose your region to compare with US sizes

Circumference (mm) UK / AUS US Size
49 5
52 6
54 7
57 8

When buying rings, getting the size right is one of the most important steps. You will want to make sure you know the correct size you need before buying, and while this sounds simple it can actually be a fairly complex process. For most people there will be a few sizes which can be worn before the ring becomes uncomfortably tight or so loose that it easily falls from the hand, so there is often a small range of sizes which are most likely to provide a good fit which is neither too close or too loose.

The size that is ultimately right for you is somewhat subjective, and depends on whether you prefer a tighter or more relaxed fit. The right ring size feels comfortable and secure, and allows for the changes your hands go through everyday. When measuring for a new ring, there are several factors you will need to consider to help you choose the right size:

  • The width of the band
  • Which hand the ring will be worn on
  • Which specific finger the ring will be worn on
  • How factors such as temperature and activity can affect your ring size

How to measure ring sizes

While a jeweller will always give you the most accurate ring size, it is fairly straightforward to measure a ring size at home. This can be done using a ring sizer which measures the finger, a sizer which measures a ring you already own, or using string. The string method simply involves taking a piece of string and wrapping it about the base of the finger the ring will be worn on. It must fit at skin level without putting pressure on the finger.

Once the tension is right, a pen can be used to mark where the ends of the string overlap to form a circle, and this will be measured to get an accurate ring size.

How to measure your ring size

The more accurate the reading, the better the fit will be, so measure down to the closest millimetre where possible to get a good estimate of your required size. Ring sizers which measure the finger are one of the most reliable ways to measure your hand for a ring at home and they are very easy to use. Slide the sizer onto your finger and pull the end until it fits closely to your skin at the base of your finger. The benefit of these sizers is that they can be taken on and off in the same way as a ring to give you an idea of how well the ring will fit. The ideal size will fit comfortably and will pass over your knuckle with some minor resistance.

If you have a ring which fits you well and you are looking for a new ring for the same finger then sizing the existing jewellery can give you one of the most accurate ring measurements at home. Place the ring over the sizer and guide it down until the inner part of the ring sits in contact with the surface of the sizer, ensuring that the ring is kept level.

Do not force the ring as it may become stuck or may provide you with an inaccurate size reading. One thing to bear in mind is that rings which are not perfectly round can give a slightly smaller reading than their true size, so use a ring which is in good condition for the most accurate ring size measurement. You can also use sliding calipers to measure the diameter of the ring and get a very accurate reading.

While different finger types have obvious size differences, the corresponding fingers on each hand do also vary in size somewhat. It is not uncommon, for example, for the ring finger on the left hand to be slightly smaller or larger than the ring finger of the other hand. These variations are usually subtle but can sometimes be as different as a size or two.

This is completely normal, but should be taken into consideration when measuring for a new ring. Generally speaking, women’s ring sizes tend to run smaller than men’s, with 6 being the average US ring size for women, which is an L in UK women’s ring sizes and a 51 in European ring sizes.

Our hands are always largest at the end of the day or after physical activity, so this is when you should measure your fingers as it guarantees that the ring will never become uncomfortably tight. The same goes for temperature - when cold hands are measured for a ring they will usually give an inaccurate sizing which is too small to be comfortable, so hands should be measured when they’re warm.

The width or the band and type of ring will also have a bearing on which size will give the best fit. Generally speaking, wide bands can feel tighter on the finger than a narrow band of the same internal diameter and this is extremely apparent when choosing rings of a 5mm width or wider, though this effect sometimes happens with narrower bands on more petite hands.

Rings also have differently shaped cross sections which can affect the fit. Comfort fit rings, also called flat court bands, feel more loose on the hand as they are designed to be slid on and off easily. Whatever the width or cross section of the ring, if your finger falls between sizes you should always choose the size up rather than down.

Things can become a little more complex when buying a ring as a gift or for an engagement, especially if you are trying not to give the game away. Rings can be some of the trickiest pieces to buy as a gift; the best way to measure for a ring as a surprise gift or for an engagement is to ask close friends and family if they happen to know her ring size, or to measure an existing ring that she wears on the same finger.

If you can borrow one of her rings for a moment you can put it on one of your own fingers and mark it with a pen. Then use a ring sizer to measure to point on your own finger that the ring fit snugly. Luckily, most rings can be resized easily or swapped for an alternative size.

US, UK and European ring sizes explained

Ring sizing in the US and Canada is numerical and runs from size 3 which is the smallest, to size 13 which is the largest. Each Canadian and US ring size is divided into quarter and half sizes to give a better fit. US ring measurements are taken in inches or millimetres and are measured from the inner circumference of the ring. You will also see US ring sizes given as a diameter, and this is the measurement across the length of the ring.

European ring sizes are given numerically and correspond to the ring’s circumference. For example, a finger which measures 48mm in circumference would fit a size 48 ring with a 15.3mm diameter. Womens’ European ring sizes run from 43 to 60, while mens’ are numbered 60 to 75. UK ring sizing is a little different and each size is assigned a letter of the alphabet from A to Z, with A being the smallest.

For inspiration on how to wear rings, check our stacking ring guide