Best Cheap Smart Ring Under £100 (UK, 2026)

The best cheap smart rings under £100 in 2026: the COLMI R02 and R10 compared, what budget rings track well, and where the gap to Oura really shows.

An affordable smart ring worn on a finger
Updated
By Rob Griffiths24 June 2026 · 7 min read
An affordable smart ring resting on a desk

You do not have to spend £300 on a smart ring. A whole budget tier exists under £100, led almost entirely by COLMI's R-series, with a long tail of near-identical generic rings sold under different names. They track the basics, charge nothing per month, and for a lot of people that is genuinely enough.

This is an honest buyer's guide to what £30 to £100 actually buys, where the budget rings hold up surprisingly well, and where the gap to an Oura Ring 4 is real. If you are still deciding whether any ring is worth it, start with our are smart rings worth it guide.

What do you actually get for under £100?

More than you might expect

The core sensing is the pleasant surprise. Budget rings use the same basic optical approach as the premium ones, and in side-by-side tests their heart-rate and blood-oxygen readings land surprisingly close to a smartwatch. Step counting is fine, and you get a continuous heart-rate trend, overnight SpO2, and a basic sleep summary - all with no subscription, which is the whole appeal.

The COLMI R10 even adds a charging case that pushes total standby toward a month, and a titanium-steel shell with proper IP68 water resistance. For tracking trends - is my resting heart rate creeping up, am I roughly sleeping enough - a budget ring does the job.

What don't you get at this price?

The gaps are real and worth knowing

Sleep is the weak spot. Budget rings tend to record time in bed rather than true sleep, and their sleep-stage breakdown - light, deep and REM - is far less reliable than Oura's, so take the stage chart with a pinch of salt. You also miss the interpretation layer: there are no polished readiness or recovery scores turning raw numbers into guidance, and the apps are functional rather than refined.

Then there is the long tail of ownership: less validation of the accuracy claims, shorter or vaguer warranties, and uncertain long-term app support. None of that matters if you want a cheap tracker; all of it matters if you want a coaching-style health companion.

The best budget smart rings

Two COLMI models cover almost everyone

BUDGET PICK

COLMI R02 Best value

The cheapest credible smart ring

  • First-time buyers
  • Basic tracking
  • Tightest budgets
  • Price Around £30
  • Battery 3 – 5 days
  • Charging case No (charges direct)
  • Best for Trying a ring cheaply
The R02 is the entry point to the whole category. For around £30 it tracks heart rate, blood oxygen and sleep with no subscription, and the core readings are decent. The trade-offs are a short 3-to-5-day battery, no charging case, and budget materials, but as a way to find out whether ring tracking suits you at all, nothing else comes close on price.

What we liked

  • Astonishingly cheap entry point
  • Decent heart-rate and SpO2 readings
  • No subscription, ever

Watch out for

  • Short 3 – 5 day battery
  • Weak sleep-stage accuracy
  • Basic build and app

BEST BUDGET OVERALL

COLMI R10 Best budget overall

Budget tracking with a charging case

  • Everyday wear
  • Longer battery
  • Swimmers
  • Price Around £50 – 60
  • Battery Days, plus case
  • Charging case Yes (up to ~30-day standby)
  • Best for Best budget all-rounder
The R10 is the budget ring most people should buy. It adds the things the R02 lacks - a titanium-steel shell, 5ATM and IP68 water resistance for swimming, and a charging case that stretches total standby toward a month - while keeping the subscription-free, sub-£60 pricing. It is the closest a budget ring gets to feeling like a premium one day to day.

What we liked

  • Charging case for long standby
  • Titanium-steel build, IP68 swimming-safe
  • Still no subscription, still under £60

Watch out for

  • Sleep staging still trails premium rings
  • App is functional, not polished

How accurate are budget smart rings?

Better than the price suggests, with one caveat

For heart rate, blood oxygen and steps, budget rings are genuinely close to premium ones in everyday use - the underlying sensors are not that different. Where the price shows is in sleep: the stage breakdown is the least reliable part, and you should treat deep and REM figures as rough indicators rather than facts.

The honest summary is that a budget ring is accurate enough for trends and awareness, but if you are making decisions off precise sleep-stage or recovery data, the validated accuracy and algorithms of an Oura or RingConn are what you are paying extra for.

Who should buy a budget smart ring?

The clear-cut buyer

Buy a budget ring - realistically a COLMI R10, or an R02 if money is tight - if you want to track heart rate, activity and rough sleep trends without a subscription, or if you simply want to try ring tracking before committing to a premium one. For most casual users it is the sensible starting point.

Step up to a premium, subscription-free ring like the RingConn Gen 3, or an Oura, if accurate sleep staging, readiness scoring and a polished app matter to you, or if you will act on the data rather than just glance at it.

Frequently asked questions

Q01Are cheap smart rings any good?
For the basics, yes. Budget rings like the COLMI R-series track heart rate, blood oxygen and steps about as accurately as premium ones, with no subscription. Their weak point is sleep-stage accuracy and the lack of a polished app and readiness scoring. As a no-frills tracker for around £30 to £60, they are good value.
Q02What is the best smart ring under £100?
The COLMI R10 is the best all-rounder under £100, adding a charging case, IP68 water resistance and a titanium-steel build for around £50 to £60. The cheaper COLMI R02, at roughly £30, is the best pick if you want to try a ring on the tightest budget.
Q03Do cheap smart rings have a subscription?
No. COLMI and most budget rings include all their features at no extra cost, which is a key advantage over the Oura Ring's monthly membership. Just be wary of unbranded clones with poor apps and uncertain data handling.
Q04How accurate is a budget smart ring's sleep tracking?
Less accurate than premium rings. Budget rings tend to log time in bed rather than true sleep and struggle to classify deep and REM stages reliably. Use the sleep data for rough trends rather than precise stage-by-stage analysis.

Related guides

COLMI R02 Review

Our closer look at the cheapest credible smart ring - what it does well and where it cuts corners.

RingConn Gen 3 Review

Stepping up without a subscription - the best-value premium ring and what the extra money buys.
Are Smart Rings Worth It?

Are Smart Rings Worth It?

The honest case for and against a smart ring before you spend anything at all.
Best Smart Ring Gifts UK 2026

Best Smart Ring Gifts UK 2026

Buying a smart ring as a present? The sizing and subscription traps to avoid, plus picks by budget.

Sources: COLMI product specifications; independent budget-smart-ring accuracy testing and user feedback (current at June 2026). Prices vary by retailer and model - check the current price and confirm which app a ring uses before buying.