Method 1: Paper or String (DIY)
   

• Use a thin strip of paper or non-stretch string, a pen, and a ruler with millimeter (mm) markings
  
• Wrap it snugly around the base of your finger
  
• Mark where it overlaps, then measure the length in mm
  
• Match your measurement to our sizing chart
  

Method 2: Online or App-Based Sizing Tools

These tools are a helpful way to estimate your ring size, especially if measuring an existing ring.
Results may vary and should be used as a reference only.

Examples:

• Web-based: ringsizer.moonmagic.com
• App-based: Ring Sizer (iOS & Android)

Method 3: In-Person Sizing

If available, a local jeweler or retailer with a ring sizing kit can help size your finger accurately.

Please note: Ring sizing methods and standards may vary between jewelers. Smart rings are typically wider than traditional rings, so fit may feel different.

Important Fit Tips

• Sensor Placement: You will wear the ring so the sensors face your palm
• Snug Fit Matters: The ring should feel secure, not tight or loose
• Time of Day: Fingers can swell, so measure at the end of the day
• Knuckles: Choose a size that fits the base of your finger, not the knuckle
• No Half Sizes: If you’re between sizes, we recommend sizing up

Best Finger for Accuracy

• Index Finger: Best choice for optimal signal quality
• Middle or Ring Finger: Suitable alternatives if the index finger is uncomfortable
• Non-Dominant Hand (Recommended only): Advised to reduce activity “noise” and minimize scratches from daily use