Please read our sizing page
The Circular ring sizes use the standard US ring sizes scale.
If the size does not fit when you receive your ring, you'll have 14 days upon delivery to change it for free (except shipping) if your ring is unworn and intact.
For Generation 2 (Circular Ring 2)
The ring comes in 9 different sizes from US 6 to US 14. We don't do half sizes. Circular Ring sizes run about one-half size above standard ring sizes. For example, if you normally wear a standard size 9, we recommend choosing a size 10 for the best comfort.
We offer different options to find your size, from the most accurate to the least accurate method.
- The most accurate way to find your size is with our Sizing Kit. This kit includes a full set of plastic rings in every size, so you can try them on at home before receiving your actual Circular Ring.
The kit costs $5, and you can order yours separately here or directly with your ring.
- If you have access to a 3D printer, you can print your sizing rings here.
- Comparison of Circular size against other smart rings:
- Circular ring 2 size = "Oura Gen 3" & "Oura Gen 4" size
- Circular ring 2 size = Samsung galaxy" size
- Circular ring 2 size = "Ringconn 2" size + 1 (e.g., size 6 Circular = size 7 Ringconn)
- Circular ring 2 size + 1 = "Ultrahuman Air" ring size (e.g., size 7 Circular = size 6 Ultrahuman)
Size 6 = 16.5 mm diameter
Size 7 = 17.3 mm diameter
Size 8 = 18.1 mm diameter
Size 9 = 18.9 mm diameter
Size 10 = 19.7 mm diameter
Size 11 = 20.5 mm diameter
Size 12 = 21.3 mm diameter
Size 13 = 22.1 mm diameter
Size 14 = 22.8 mm diameter
- An easy-to-use digital sizing tool to help you find the right fit for your smartphone.
Click here if you're on Mobile.
Scan the QR code below with your Mobile if you're on a computer.
You will find 3 options:
- AI-based Photo Sizing with a reference: Take a picture of your hand with a reference card.
- Ring Comparison: Place a ring you already own on screen to match with Circular’s size guide.
- Size Conversion Guide: Use our mm Guide for equivalency.
If you have issues with the AI photo sizing tool
Make sure to meet these requirements for the picture:
✔️ Good lighting
✔️ Plain background
✔️ Spread fingers
✔️ No rings
✔️ Follow the example image closely in terms of hand-phone distance
NOTE: Make sure to get **multiple **measurements with the same results.
NOTE: If you’re unsure of the accuracy you can visit any local jeweler to find your US equivalent finger size. Circular Ring sizes run about one-half size above standard ring sizes. For example, if you normally wear a standard size 9, we recommend choosing a size 10 for the best comfort.
For Generation 1
Here is the free Circular sizing guide to be printed
Here is the free Circular rings to be 3D printed