Oura Ring 5 vs 4: what changed, what didn't, and what you'll keep paying

The verdict

What changed from Ring 4 to Ring 5

Oura announced Ring 5 on May 28, 2026. Pre-orders opened that day and shipping started June 4, according to TechCrunch, which described it as a thinner, lighter design. Here's what the two rings' own pages say:

• Sizes: Ring 5 comes in 6-13. Ring 4 runs from 4 to 15. Oura says Ring 5's “redesigned interior fits differently than Oura Ring 4.”
• Battery: Ring 5 claims “up to 6-9 days of battery life, depending on ring size and usage.” Ring 4 claims “typically 5-8 days.”
• Materials: Ring 5 is titanium inside and out, and Oura lists it “from 2 grams (depending on ring size).” Ring 4 is “titanium with physical vapor deposition (PVD) or Diamond-like Carbon (DLC) coating.” We didn't find a Ring 4 weight in the pages we checked.
• Water: Ring 5 is “waterproof up to 100m/328 ft” and IP68. Ring 4 is rated to 100 m and described as “suitable for sauna and water sports but not diving.”
• Availability: Ring 5 is the only ring on Oura's US ring store. Ring 4's product page is still live but shows no price and points you to Ring 5 and an “Upgrade FAQ.” Both are listed on Amazon.com.
• Membership: unchanged. Same plan, same price, same limits without it.

There's also an Oura Ring 4 Ceramic (zirconia ceramic over a titanium inner shell, with the same 5-8 day claim as Ring 4). Its product page was live with no sold-out notice when we checked, but it didn't show a price either.

Oura Ring 4 vs 5 sizing

This is the question people search most, and the honest answer is short: your Ring 4 size doesn't tell you your Ring 5 size. Oura says Ring 5's interior “fits differently than Oura Ring 4,” and more generally that “the sizing for each Oura Ring model differs slightly between generations” ( Oura Support). Oura also uses whole sizes only, and they “differ slightly from standard US ring sizes, so it's important to test with our sizers even if you know your usual ring size.”

What that means in practice:

• Resize for Ring 5, even if you own a Ring 4. Oura's sizing kit is free on its own store, and it's sold on Amazon with a matching credit toward the ring, per Android Police. The Amazon listing is titled “Unique Sizing, Not Standard Ring Sizing.”
• If you're at the ends of Ring 4's range, Ring 5 may not come in a size that fits you. Ring 4 covers sizes 4, 5, 14 and 15; Ring 5 doesn't. Only Ring 5's own sizer can tell you whether its 6 or 13 works for your finger.
• Use the finger you'll wear it on. Oura recommends the index finger for the best accuracy, and finger sizes differ. See which finger to wear a smart ring on.

If you need a very small or very large size, our smart rings for large and small sizes covers every brand's range, and smart ring sizing compared explains why no brand's sizes match another's.

Battery: claims and reports

On paper, Ring 5 adds about a day: 6-9 days against Ring 4's 5-8. Both are Oura's own claims, and Oura ties Ring 5's figure to ring size and usage. The one real-world Ring 5 number we have is DC Rainmaker's: he got 6-7 days (DC Rainmaker). Neither ring comes with a charging case.

Two warranty facts matter more for battery than the day of difference. First, Oura's one-year US warranty excludes batteries as consumable parts, on both rings. Second, Android Authority reported that Oura's pre-IPO filing showed an 84.4 million dollar increase in warranty expenses during fiscal 2025, tied to Ring 4 battery problems (Android Authority). The report is about battery performance, not swelling, and it doesn't tell you how many rings were affected. If you buy a Ring 4 now, factor it in. Our guides to smart ring battery life and battery lifespan and replacement cover what happens as a sealed ring battery ages.

What the evidence says

This is Ring 4's strongest card. Dial et al. (Physiological Reports, 2025) tested Oura Gen 3 and Gen 4 rings against a Polar H10 chest strap across 536 nights in 13 adults. The Oura rings had the highest agreement of the wearables tested, and for Gen 4 the resting heart rate error was 1.94% and HRV error 5.96% (Dial et al.). Ring 4 is the model that study measured directly.

We found no published validation study of Ring 5 yet. Its evidence is inherited: Oura's earlier rings have the strongest independent validation of any ring we found, and Ring 5 is their successor. The best Ring 5-specific data is DC Rainmaker's review. Against a Polar H10, its workout heart rate was “largely pretty good” for indoor cycling and road running, but on a trail descent “the HR accuracy basically falls apart for the entire rest of the run.” For sleep he saw “no meaningful difference between Oura and other wearables for core sleep stats.” Our smart ring accuracy guide lists every Oura study with its funding.

Features and health claims

Oura's Ring 5 page lists heart rate, HRV, blood oxygen, temperature trends, Symptom Radar, Cardiovascular Age, Blood Pressure Signals and Cycle Insights. Most of those need the membership. We didn't find a matching feature list for Ring 4 in the pages we checked, so we can't tell you which of these reach Ring 4 as well. Ask Oura before you buy one for a specific feature.

The same membership on both

Whichever Oura you pick, the running cost is identical. The Oura Membership is $5.99 a month or $69.99 a year in the US, with one month included for new members and no lifetime plan. Without it, Oura says you see only “your three daily Oura scores (Readiness, Activity, and Sleep), ring battery, basic profile information, app settings, and the Explore content” (Oura Support).

Oura says most items on its online store can be bought with HSA or FSA funds, and prepaid membership can be too when you buy it with a new ring (Oura Support). The rules have fine print; see smart ring HSA/FSA eligibility. For the full fee breakdown, read what the Oura membership costs, and for the value question, is the Oura Ring worth it?

Side by side

On our ring rubric (methodology), Ring 4 scores 6.0 and Ring 5 scores 5.8. Ring 4 edges ahead on evidence, because it's the model the study tested, and on size range. Ring 5 wins on claimed battery. Both lose most of their points on cost of ownership, because of the membership.

Buying a Ring 4 now

With Ring 4 off Oura's ring list, most buyers will find it at other retailers. After Ring 5 launched, Gizmodo reported an Amazon clearance discount on the Gold and Rose Gold Ring 4 (Gizmodo). We don't print the figure, because prices move; the buy button below goes to Amazon's current listings. Before you buy:

1. Get sized for Ring 4 specifically, not with a Ring 5 kit, since the two fit differently. Ask the seller or Oura which sizer matches Ring 4.
2. Keep your receipt. Oura's US warranty runs “one year from the date of purchase,” and refurbished units get a 90-day limited warranty. Batteries are excluded either way.
3. Budget the membership, not just the ring. A discounted ring with a full-price plan is still a plan.

Our Oura Ring 4 review goes deeper, and smart ring warranty and returns compares every brand's terms.

Should Ring 4 owners upgrade?

Probably not, if your Ring 4 still holds a charge you can live with. You'd buy a ring again while your membership cost stays exactly where it was, and you'd give up the model with direct chest-strap validation for one without it (so far). The case for upgrading is battery: if your Ring 4 has faded, Ring 5's longer claim and a fresh battery may be worth it, especially since batteries aren't covered by Oura's warranty. Resize first. If you're upgrading anyway, it's also a natural moment to ask whether you want to keep paying at all; our Oura vs RingConn comparison puts the fee against the evidence.

Who should buy which

• Oura Ring 5: you fit 6-13, you want the current model and the longest Oura battery claim, and you'll pay the membership. See the Oura Ring 5 review.
• Oura Ring 4: you need size 4, 5, 14 or 15, or you want the directly validated model, and you can find one at a fair price with a clear warranty.
• RingConn Gen 2: you like what Oura does but not what it charges. See the best smart rings without a subscription.

Weighing a different Oura rival? Try Circular Ring 2 vs Oura, Oura vs Galaxy Ring, or browse the compare hub.