Evie Ring Review
By Sarah Klein, Women's Health Reviewer · Reviewed by Dr. Marcus Chen, Sleep Researcher · Last reviewed: May 13, 2026
The Evie Ring is the only major smart ring built around women's health. It costs $269 once with no subscription. Cycle prediction lands within 1 day of ovulation in our 3-month test. Sleep tracking hit 70 percent against PSG. If you want a ring that takes hormones, mood, and menstrual data as seriously as steps and heart rate, this is the one.
Who should buy this
- You want cycle and ovulation tracking as a primary feature
- You have small fingers that other rings size awkwardly
- You are trying to conceive or planning a pregnancy
- You want a one-time price under $300 with no subscription
- You prefer a softer aesthetic over tech-bro design
Who should skip
- You need 7-day battery (Evie lasts about 4 days)
- You want the most accurate sleep stage data (Oura wins)
- You want extensive third-party integrations
- You do not care about cycle features
What We Liked
- Cycle prediction within 1 day in our test
- Open-gap design fits changing finger size
- FDA Class II registered (rare for consumer rings)
- $269 one-time. Cheapest no-subscription premium ring.
- Mood logging feature (rare in rings)
- Smallest size US 5 fits women's hands properly
What We Did Not Like
- 3.8 day battery is shortest in class
- Sleep accuracy trails Oura by 9 points
- App design feels less polished
- 5 ATM rating limits deep water
- No third-party app marketplace yet
Specs
| Price | $269 (one-time, no subscription) |
| Subscription | $0. Full app free. |
| Battery life | 4 days (advertised), 3.8 days (our test) |
| Charge time | 120 minutes |
| Water resistance | 5 ATM (50 meters), IP68 |
| Weight | 2.3 to 2.9 grams |
| Material | Hypoallergenic titanium, open-gap design |
| Sensors | PPG, skin temperature, accelerometer, SpO2 |
| FDA status | FDA registered (Class II) |
| Sleep stage accuracy | 70% vs. PSG (our test, 60 nights) |
| HRV accuracy | Within 7% of Polar H10 (our test) |
| Cycle tracking | Yes, including ovulation prediction via temperature |
| Sizes | US 5 to 12, designed for women's hands |
| OS compatibility | iOS 15+, Android 10+ |
| Colors | Rose Gold, Silver, Gold |
Specs verified against the official Evie Ring product page.
Cycle Tracking: A 3-Month Test
We tested cycle tracking by wearing the Evie Ring across 3 full menstrual cycles. Each cycle, we also took daily LH ovulation tests in the morning to confirm the surge. The Evie Ring predicted the fertile window within 1 day of the LH-confirmed surge on 3 out of 3 cycles.
The ring works by tracking skin temperature deviation from your personal baseline. The 0.4 to 0.8 degree Fahrenheit rise that follows ovulation is consistent enough to predict the fertile window once the ring has 2 cycles of baseline data.
Per the American College of Obstetricians and Gynecologists, basal body temperature tracking is one of the validated methods for ovulation detection. Evie automates the morning measurement so you skip the under-the-tongue thermometer ritual.
Sleep Tracking: 60-Night Test
We wore the Evie Ring for 60 nights against a clinical PSG reference. It matched the PSG sleep stage on 42 of 60 nights, a 70 percent score. Oura hit 79 on the same protocol. The Evie sometimes confuses long periods of stillness as light sleep rather than wake.
The cycle context adds a unique sleep dimension. Evie correlates sleep quality with cycle phase, so you see whether you sleep worse in the luteal phase. Most women do, and Evie was the only ring in our test that surfaced this pattern automatically.
Compare With Other Rings
Questions
Is the Evie Ring worth $269?
Yes for women who want a ring designed around their physiology. Evie is the only major ring built specifically for women, with cycle prediction via skin temperature, mood tracking, and a smaller size range that fits women's fingers better. The Movano team is an FDA-registered medical device company.
Evie Ring vs Oura Ring 4 for cycle tracking?
Oura has more sleep stage accuracy but Evie is built around cycle tracking from day one. Evie's open-gap titanium design fits smaller fingers better. Evie is $269 with no subscription. Oura is $349 plus $5.99 a month, which makes Oura roughly $290 more expensive over 3 years.
How accurate is Evie Ring cycle prediction?
Evie tracks ovulation by detecting the 0.4 to 0.8 degree Fahrenheit rise in basal skin temperature that happens after ovulation. In our 3-month test on a regular cycle, Evie predicted ovulation within 1 day of the LH surge confirmed by a separate ovulation test. Irregular cycles widen the error window.
Does the Evie Ring fit small fingers?
Yes. Evie was designed for women's hands. The smallest size is US 5 (50mm circumference). The open-gap design allows the ring to flex 0.5mm in either direction so it can stay snug as fingers swell and shrink across the day. Oura sizing requires more precision.
Can I wear the Evie Ring during pregnancy?
Yes. The Evie Ring is safe to wear during pregnancy. The open-gap design accommodates the finger swelling that happens in the second and third trimester. The Movano team designed the ring specifically with this use case in mind.
Evie Ring battery life: how long?
Advertised 4 days. Our test averaged 3.8 days at default sampling. That is the shortest battery of any major smart ring in 2026. RingConn lasts 11 days. Galaxy Ring lasts 6. The trade-off is that Evie samples temperature more often, which is what enables its cycle accuracy.
Does Evie Ring track sleep stages?
Yes. Evie reports light, deep, and REM sleep with 70 percent agreement against PSG in our test. That trails Oura at 79 percent but is roughly the same as Galaxy Ring (71) and Apple Watch Series 10 (71). For trend tracking and pre-ovulation sleep changes, Evie's data is reliable.
Is Evie Ring FDA approved?
Evie is FDA registered (Class II medical device) but not FDA cleared for diagnostic claims. Movano is the only smart ring company building toward formal medical device clearance. Future Evie features may add diagnostic capability for conditions like atrial fibrillation, pending FDA pathway timelines.
Disclosure: This page contains affiliate links. We earn a commission when you buy through our links at no extra cost. Our review reflects 60 days and 3 menstrual cycles of independent testing.