We know it can be tough to select a size online, so we’ve put together a handy guide on how you can measure at home to find your perfect fit! There are a few easy methods you can use to find the right size for yourself or a loved one. We recommend printing off our size guide here. 

Kellective by Nikki Ring Sizing Guide


Option 1: Measure a Ring You Already Own

By far the simplest option is to measure one of your existing rings against our size guide print off. This is particularly helpful if you are trying to purchase a ring for a loved one or friend. All you need to do is line the inside of your ring up with one of the circles.

Option 2: Measure Your Finger

If you do not have access to a printer, then measuring your finger is your next best option. To do this, simply find a piece of string, a pen and a ruler. You will need a piece of string, a pen/marker and some measuring tape or a ruler.


  1. Cut a piece of string long enough to circle around your fingers. 
  2. Wrap it around the base of your finger at the widest part and find a snug, yet comfortable length.
  3. Using a pen or marker, mark where the ends of the string overlap.
  4. Lay the string flat against a ruler and measure the length.
  5. We suggest repeating the steps above a few times to avoid errors. 
  6. Use the guide below to find your perfect size!



The difference from one ring size to next is between 2-3mm in the circumference of the inner part of the ring’s band.

Inside Diameter

Inside Circumference

US & Canada Ring Size (Approx.)

15.6 mm

49.3 mm*


16.5 mm

51.8 mm*


17.3 mm

54.4 mm*


18.2 mm

56.9 mm*


18.9 mm

59.5 mm*



*In the Kellective office we find that measuring the circumference of your finger provides a looser fitting ring. If you want a closer fit try going down a size or two! Measuring off a ring you already have is definitely the easiest way to go!

Our Top Tips

Our hands are funny things and have a few little quirks you should keep in mind when ordering:

  • Fingers will often change size throughout the day. For this reason, it is best to measure your finger towards the end of the day (when at its largest).
  • Our dominant hands are often slightly larger - ensure you measure the finger the ring will be worn on most, on the correct hand!
  • Wider bands will have a slightly firmer fit than fine rings. if you are measuring for a gift, try to measure a ring with a similar width as the style you are purchasing.  
  • Make sure the finger is at a normal body temperature – fingers can expand or shrink when hot, cold or damp.
  • If your knuckle is bigger, take 2 measurements and choose a size between them. The ring should fit over the knuckle but not be too loose or it will shift around.
  • If the ring falls between two sizes, order the larger size up – just to be safe!
How should my ring fit?

We’ve found there’s no such thing as a perfect fit, for most a ‘good fit’ means that your ring should be ‘comfortable most of the time’. Sometimes, your ring may be slightly loose or a little snug. As a rule, rings should go on with relative ease and come off with little difficulty. Your ring should fit your fingers comfortably, snug enough that it will not fall off but loose enough to slide over your knuckle. If the ring falls between two sizes, order the larger size up – just to be safe!Shop Kellective by Nikki Rings