Smart Rings / Oura Ring 4 Ceramic (2025) vs Circular Ring 2 (2025)
Oura Ring 4 Ceramic (2025) vs Circular Ring 2 (2025)
Circular Ring 2 (2025)
The only FDA-cleared AFib ring — attached to the buggiest app in the category.
Wins overall by 0.1 points
Quick Verdict
The Circular Ring 2 (2025) wins by 0.1 points, which is not enough to settle it. A $100 ceramic shell over Ring 4 electronics, and the scratches it will get are not warrantied. Pick on the specs that matter to you, not the overall score.
The Oura Ring 4 Ceramic (2025) and Circular Ring 2 (2025) are both current-generation smart Ring models, and the Circular Ring 2 (2025) is $100 cheaper than the Oura Ring 4 Ceramic (2025) ($299 vs $399). On Subscription Freedom, the Circular Ring 2 (2025) leads (8.0 vs 2.0/10) — how much of the ring keeps working with no recurring payment — the category's defining trap. On App & Data, the Oura Ring 4 Ceramic (2025) leads (9.0 vs 4.5/10) — app stability, insight depth, platform parity and whether you can get your history out. On Sleep Tracking, the Oura Ring 4 Ceramic (2025) leads (9.3 vs 7.0/10) — sleep staging depth, overnight accuracy and how usable the morning report is. Overall, the Circular Ring 2 (2025) scores 7.1/10 across our 8 scoring categories versus 7.0/10 for the Oura Ring 4 Ceramic (2025), though the gap is close enough that your specific use case should decide it. Below, we break down the full spec sheet, category-by-category scores, and exactly who should buy which one.
Side-by-Side Comparison
| Spec | Oura Ring 4 Ceramic (2025) | Circular Ring 2 (2025) |
|---|---|---|
| Price | $399.00 | $299.00 |
| Release Year | 2025 | 2025 |
| Battery Life (claimed) (days) | 8 | 8 |
| Battery, In Practice | Same 5-8 day claim as the metal Ring 4, with the same caveat that ring size, app settings and activity level move it. 20-80 minutes to charge. | Circular publishes two numbers, not one: 8 days in power mode and 5 days in performance mode — performance mode is the one that samples more often. Tom's Guide's tester got a week or more in practice. |
| Subscription | Required in practice — $5.99/month or $69.99/year, identical to every other Oura. Paying $100 more for ceramic buys you no membership credit. | No mandatory subscription today; core features come with the ring, and some advanced screens are unlocked with in-app coins earned by wearing it. Circular has said a premium tier covering blood glucose and blood pressure is coming, with neither price nor date published — so the no-subscription position is provisional, not guaranteed. |
| 3-Year Cost of Ownership ($) | 608.97 | 299✓ |
| Sizes Offered | US 4-15, no half sizes, matching the metal Ring 4 | US 6-14 |
| Sizing Kit | Free plastic sizing kit ships before the ring; 24-hour minimum wear including overnight, adding roughly a week before the ring ships. | Two routes: a camera-and-credit-card digital sizing flow that needs no kit at all, or a $5 physical replica-ring kit. This is the only brand here that lets you skip the kit wait entirely. |
| Returns & Size Exchange | Oura does not publish a return window on its warranty page. The 1-year warranty excludes normal wear and tear; Oura's own product page states that minor scratches from everyday use are expected on the ceramic. | 14-day no-questions-asked return policy, 1-year warranty (2 years in the EU). |
| Measured vs Inferred | Identical to the metal Ring 4 — red/IR LEDs for blood oxygen, green/IR for heart rate and HRV, a temperature sensor and an accelerometer. Nothing about the ceramic shell adds a measurement. | The only ring in this comparison with actual ECG electrodes: a 40-second single-lead reading screened for atrial fibrillation. Everything else — the 140+ 'biosignals' across 13+ health features — is derived from the same PPG, temperature and motion stack every other ring uses. |
| FDA Clearance | None published. General wellness product. | Circular states, and Tom's Guide's review confirms, that the ring is FDA-cleared to monitor for irregular heartbeats indicating AFib. That clearance covers the AFib feature, not the other 140 biosignals. |
| Water Rating | Water resistant to 100m/328ft | Sources conflict: Circular's own store page lists IP68 only, while Tom's Guide's review states 50m water resistance with IP68 — either way, half the 100m rating Oura and RingConn claim |
| Phone Support | iOS and Android, full feature parity; Oura lists integrations with 40+ apps | iOS and Android |
| Charger & Data Export | Proprietary size-specific dock plus USB-C cable, and a ceramic polishing pad. Export: not published as a one-click history download; personal-access-token Cloud API only. | Proprietary charger. Export: not published by the manufacturer. Tom's Guide reported sync failures that lost whole nights of sleep data, so what reaches the app is not always complete. |
| Warranty | 12 months | 12 months |
| Colors | Midnight, Cloud, Tide, Petal | Obsidian Black, Silver, Gold, Rose Gold |
Category Scores
Subscription Freedom
The Circular Ring 2 (2025) leads clearly here, 8.0 against 2.0 — a 6.0-point margin on how much of the ring keeps working with no recurring payment — the category's defining trap. If that is what you are buying for, the Oura Ring 4 Ceramic (2025) does not close the gap elsewhere.
Sleep Tracking
The Oura Ring 4 Ceramic (2025) leads clearly here, 9.3 against 7.0 — a 2.3-point margin on sleep staging depth, overnight accuracy and how usable the morning report is. If that is what you are buying for, the Circular Ring 2 (2025) does not close the gap elsewhere.
Health Sensing
The Circular Ring 2 (2025) is marginally ahead, 8.5 to 8.2. A gap this small rarely decides a purchase on its own, though it counts if what the sensors genuinely measure — heart rate, SpO2, temperature, ECG — rather than infer is your priority.
Battery Life
The Circular Ring 2 (2025) leads clearly here, 8.0 against 7.0 — a 1.0-point margin on real days between charges with continuous sensing on, plus what the charging case adds. If that is what you are buying for, the Oura Ring 4 Ceramic (2025) does not close the gap elsewhere.
Sizing & Fit
The Oura Ring 4 Ceramic (2025) leads clearly here, 8.5 against 8.0 — a 0.5-point margin on how many sizes exist, how good the sizing kit is, and how forgiving the exchange policy is. If that is what you are buying for, the Circular Ring 2 (2025) does not close the gap elsewhere.
App & Data
The Oura Ring 4 Ceramic (2025) leads clearly here, 9.0 against 4.5 — a 4.5-point margin on app stability, insight depth, platform parity and whether you can get your history out. If that is what you are buying for, the Circular Ring 2 (2025) does not close the gap elsewhere.
Durability
The Oura Ring 4 Ceramic (2025) leads clearly here, 6.5 against 5.5 — a 1.0-point margin on finish scratch resistance, water rating in practice, and whether the finish is warrantied. If that is what you are buying for, the Circular Ring 2 (2025) does not close the gap elsewhere.
Value
The Circular Ring 2 (2025) leads clearly here, 7.0 against 5.5 — a 1.5-point margin on what the ring delivers against its total cost of ownership, not just its sticker price. If that is what you are buying for, the Oura Ring 4 Ceramic (2025) does not close the gap elsewhere.
Best For
Choose the Oura Ring 4 Ceramic (2025) if…
- • App & Data matters most to you — the Oura Ring 4 Ceramic (2025) scores 9.0/10 here (app stability, insight depth, platform parity and whether you can get your history out).
- • Sleep Tracking matters most to you — the Oura Ring 4 Ceramic (2025) scores 9.3/10 here (sleep staging depth, overnight accuracy and how usable the morning report is).
- • Your main use case is womens-health.
Choose the Circular Ring 2 (2025) if…
- • Subscription Freedom matters most to you — the Circular Ring 2 (2025) scores 8.0/10 here (how much of the ring keeps working with no recurring payment — the category's defining trap).
- • Value matters most to you — the Circular Ring 2 (2025) scores 7.0/10 here (what the ring delivers against its total cost of ownership, not just its sticker price).
- • Battery Life matters most to you — the Circular Ring 2 (2025) scores 8.0/10 here (real days between charges with continuous sensing on, plus what the charging case adds).
- • You want to spend less — it's $100 cheaper.
- • Your main use case is no-subscription or heart-health.
Pros & Cons
Oura Ring 4 Ceramic (2025)
Pros
- +The only ring here that is not metal-coloured — four ceramic finishes including a genuine pastel
- +Ceramic is harder than titanium and does not pick up the same dull scuffing
- +Same sensors, same app and same 4-15 size range as the metal Ring 4
- +$100 below its $499 list at the time of writing
Cons
- −$100 more than the metal Ring 4 for identical sensing — you are paying for the shell
- −Oura's own page warns that minor scratches from everyday use are expected, and the warranty does not cover them
- −Ceramic chips rather than scuffs: a hard knock on tile is a different failure mode from a scratched titanium ring
- −Three-year cost lands at $608.97, the same as a brand-new Ring 5
- −Still tied to the $5.99/month membership like every other Oura
Circular Ring 2 (2025)
Pros
- +The only ring here with real ECG electrodes and an FDA clearance for AFib detection
- +Digital sizing by phone camera removes the one-to-two-week sizing-kit wait every rival imposes
- +$299 with no mandatory subscription, against $608.97 over three years for a base Oura Ring 5
- +Advanced screens are earned by wearing the ring rather than billed monthly
Cons
- −The app is the weak link: Tom's Guide hit sync failures that lost sleep reports outright, and could not get the ECG feature to run during testing
- −Circular has announced a future premium tier for glucose and blood pressure with no price or date, so the no-subscription promise is not locked in
- −Water rating is half the category norm, and sources disagree on whether it is 50m or IP68-only
- −Titanium finish was described as scratch-prone, and the interior sensors protrude enough to leave marks on the finger
- −Fitness tracking is thin next to Samsung and Oura — this ring is aimed at cardiac screening, not training
Shop by Need
FAQs
Is the Oura Ring 4 Ceramic (2025) or Circular Ring 2 (2025) better overall?+
Based on our 8-category scoring, the Circular Ring 2 (2025) comes out ahead overall. See the full breakdown in the scores section above — the right pick still depends on which categories matter most for your use case.
Which is better for Subscription Freedom, the Oura Ring 4 Ceramic (2025) or the Circular Ring 2 (2025)?+
The Circular Ring 2 (2025) scores higher on Subscription Freedom (8.0/10 vs 2.0/10) — how much of the ring keeps working with no recurring payment — the category's defining trap.
Which is better for App & Data, the Oura Ring 4 Ceramic (2025) or the Circular Ring 2 (2025)?+
The Oura Ring 4 Ceramic (2025) scores higher on App & Data (9.0/10 vs 4.5/10) — app stability, insight depth, platform parity and whether you can get your history out.
Which is better for Sleep Tracking, the Oura Ring 4 Ceramic (2025) or the Circular Ring 2 (2025)?+
The Oura Ring 4 Ceramic (2025) scores higher on Sleep Tracking (9.3/10 vs 7.0/10) — sleep staging depth, overnight accuracy and how usable the morning report is.
Which is better for Value, the Oura Ring 4 Ceramic (2025) or the Circular Ring 2 (2025)?+
The Circular Ring 2 (2025) scores higher on Value (7.0/10 vs 5.5/10) — what the ring delivers against its total cost of ownership, not just its sticker price.
Is the Oura Ring 4 Ceramic (2025) worth the price difference over the Circular Ring 2 (2025)?+
The Circular Ring 2 (2025) is the cheaper option at $299 versus $399. Whether the pricier model is "worth it" depends on how much you value its lead in Subscription Freedom.
Which is better suited to my use case?+
The Oura Ring 4 Ceramic (2025) is the better fit if you mainly care about womens-health. The Circular Ring 2 (2025) is the better fit for no-subscription or heart-health.
What's the warranty on the Oura Ring 4 Ceramic (2025) vs the Circular Ring 2 (2025)?+
The Oura Ring 4 Ceramic (2025) ships with a 12-month warranty; the Circular Ring 2 (2025) ships with a 12-month warranty. Always confirm current terms on the manufacturer's site before buying.
Should I wait for the next model instead of buying either of these?+
If either model is more than two years old, a successor may be close — check the "Latest Model" link on each product page. Otherwise, both are current, well-supported options and there's no strong reason to wait.
Cheaper Option
Circular Ring 2 (2025) — $299.00
Premium Option
RingConn Gen 3 (2026) — $349.00
Specifications and prices for both products last verified . Scores are calculated from published specifications — see how we compare products.