Evie Ring Size Chart & Fit Guide
An independent, comprehensive sizing reference for the Evie Ring by Movano Health. Compare sizes 5 through 12 in millimeters, understand how the signature open-gap design accommodates cyclical finger swelling, and learn how to use the official sizing kit.
How Does Evie Ring Sizing Work?
Evie Ring Sizing Table
Comprehensive sizing chart mapping Evie sizes 5–12 to inside diameter, circumference, and regional standard sizes.
| Evie Size | US / Canada | UK / Australia | EU / ISO | Inside Diameter (mm) | Inside Circ. (mm) | Fit & Open-Gap Notes |
|---|---|---|---|---|---|---|
| Evie SizeSize 5 | US / Canada5.0 | UK / AustraliaJ½ | EU / ISO49.5 | Inside Diameter (mm)15.70 mm | Inside Circ. (mm)49.32 mm | Fit & Open-Gap NotesSmallest Evie Ring size. Designed for petite ring fingers; open gap provides gentle knuckle expansion. |
| Evie SizeSize 6 | US / Canada6.0 | UK / AustraliaL½ | EU / ISO52.0 | Inside Diameter (mm)16.51 mm | Inside Circ. (mm)51.87 mm | Fit & Open-Gap NotesStandard women’s size 6. Accommodates subtle size 6.25 variations due to flexible open-band gap. |
| Evie SizeSize 7 | US / Canada7.0 | UK / AustraliaN½ | EU / ISO54.5 | Inside Diameter (mm)17.32 mm | Inside Circ. (mm)54.41 mm | Fit & Open-Gap NotesMost common women’s index/middle finger size. Recommended index finger placement for highest sensor fidelity. |
| Evie SizeSize 8 | US / Canada8.0 | UK / AustraliaP½ | EU / ISO57.0 | Inside Diameter (mm)18.14 mm | Inside Circ. (mm)56.99 mm | Fit & Open-Gap NotesPopular middle or index finger size. If your knuckle measures 8.5, size up to 9 for easy slide. |
| Evie SizeSize 9 | US / Canada9.0 | UK / AustraliaR½ | EU / ISO59.5 | Inside Diameter (mm)18.95 mm | Inside Circ. (mm)59.53 mm | Fit & Open-Gap NotesComfortable fit on index or middle finger. Open gap flexes comfortably during workout or heat swelling. |
| Evie SizeSize 10 | US / Canada10.0 | UK / AustraliaT½ | EU / ISO62.0 | Inside Diameter (mm)19.76 mm | Inside Circ. (mm)62.08 mm | Fit & Open-Gap NotesLarger women’s index or thumb size. 8.0 mm band distributes pressure evenly across the finger base. |
| Evie SizeSize 11 | US / Canada11.0 | UK / AustraliaV½ | EU / ISO64.5 | Inside Diameter (mm)20.57 mm | Inside Circ. (mm)64.62 mm | Fit & Open-Gap NotesLarge finger or thumb size. Optical sensors maintain contact without rotating. |
| Evie SizeSize 12 | US / Canada12.0 | UK / AustraliaX½ | EU / ISO67.0 | Inside Diameter (mm)21.39 mm | Inside Circ. (mm)67.20 mm | Fit & Open-Gap NotesLargest manufactured Evie Ring size. No sizes 13 or 14 are produced. Fits circumferences up to ~67.2 mm. |
Smart Ring Sizing: Evie Ring vs Leading Alternatives
How the Evie Ring's unique open-gap construction compares with closed-loop smart rings.
Evie Ring
- Width: 8.0 mm
- Thickness: 3.0 mm
- Size Range: US 5 to 12
- Shape: Split-shank open gap
- Fit Nuance: Adapts to hormonal water retention & knuckle swelling.
RingConn Gen 2
- Width: 6.8 mm (slimmest)
- Thickness: 2.0 mm
- Size Range: US 6 to 14
- Shape: Squircle profile
- Fit Nuance: Anti-rotation corners; closed rigid titanium band.
Samsung Galaxy Ring
- Width: 7.0 mm
- Thickness: 2.6 mm
- Size Range: US 5 to 13
- Shape: Concave circular band
- Fit Nuance: Fixed concave titanium; 3 raised interior sensor bumps.
Oura Ring Gen 3 / 4
- Width: 7.9 mm
- Thickness: 2.55 mm
- Size Range: US 6 to 13 / 14
- Shape: Flat exterior circular band
- Fit Nuance: Dome sensor bumps; rigid titanium construction.
The 24-Hour Evie Sizing Kit Protocol
How to test sample open-gap plastic rings and choose your ideal Evie Ring size.
- Select your target finger: Movano Health officially recommends the index finger for optimal vascular access to the radial digital artery. Middle and ring fingers are also suitable alternatives.
- Check the gap alignment: Place the open gap facing outwards or inwards according to personal comfort. Ensure the optical sensors on the band rest flush against the palm side of your finger.
- Test across cyclical fluctuations: Women's finger volume naturally expands during luteal menstrual phases, workouts, warm temperatures, and overnight sleep. Wear the sizing ring for at least 24 continuous hours to observe fit changes.
- Evaluate knuckle friction: When sliding the ring off, you should feel slight resistance at the knuckle. The open gap will gently flex to assist removal without causing discomfort.
Source and verification
Table source: Movano Health — Evie Ring Sizing & Fit Guide. Last reviewed . Check the retailer's current size guide before ordering.
Frequently asked questions
How does the Evie Ring open-gap design affect sizing and comfort?
The Evie Ring by Movano Health features an innovative split-shank open gap rather than a continuous solid loop. This gap allows the ring to naturally flex and expand by approximately 0.5 to 1.0 mm, making it substantially easier to slide over prominent knuckles and accommodating cyclical finger swelling without constricting blood circulation.
Does the Evie Ring adapt to hormonal water retention and finger swelling?
Yes. Unlike rigid smart rings that can feel painfully tight or get stuck during menstrual bloating, pregnancy, or high ambient heat, the Evie Ring was specifically engineered around women’s biometric cycles. The flexible open-band architecture gently expands as fingers swell overnight or during luteal phases, maintaining accurate optical sensor contact without pinching.
What sizes are available for the Evie Ring?
The Evie Ring is offered in 8 whole sizes: US 5, 6, 7, 8, 9, 10, 11, and 12. Movano Health does not produce half sizes (e.g., 6.5 or 7.5), nor does it offer extended sizes 13 or 14. Petite sizes 5 and 6 are well-supported, catering directly to smaller hands.
Which finger is recommended for wearing the Evie Ring?
Movano Health officially recommends wearing the Evie Ring on your index finger for the highest biometric data precision. The middle and ring fingers are also fully approved alternatives if the index finger feels too snug or wide. Wearing the ring on your thumb or pinky finger is discouraged because irregular contact can degrade pulse and blood oxygen readings.
What should I do if I am between sizes on the Evie sizing kit?
If you find yourself between two sizes (such as a 7.5), Movano Health generally recommends testing both plastic sizing rings for at least 24 hours. Because the open gap provides minor flex, a smaller whole size (e.g., 7) may fit comfortably if your knuckle allows passage; however, if you have pronounced knuckles or experience frequent swelling, sizing up to the larger whole size (e.g., 8) is recommended for long-term comfort.
What are the dimensions and materials of the Evie Ring?
The Evie Ring has an 8.0 mm band width and is 3.0 mm thick at the sensor housing. It features a scratch-resistant liquidmetal exterior shell with smooth, rounded edge finishes to prevent snagging on clothing or hair. Despite its substantial width, the open design keeps it lightweight and breathable.
Can a jeweler resize the Evie Ring?
No. The Evie Ring is a medical-grade smart wearable packed with fragile micro-sensors, flex PCBs, and a curved lithium-polymer battery. Any jeweler attempts to bend, solder, or resize the ring will instantly ruin the electronics and nullify the manufacturer warranty.