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Circul Smart Ring vs FITTR HART Smart Ring
Side-by-side comparison of manufacturer specifications: weight, size, battery life, sensors, app compatibility and subscription fees.
By Gil Sapir, Editor ยท Data compiled from manufacturer specifications and public sources (methodology).
โกโก Quick-Decision Verdict: Circul Smart Ring vs FITTR HART Smart Ring
โก Quick-Decision Verdict: Circul Smart Ring vs FITTR HART Smart Ring
Spec-based comparison of Circul Smart Ring and FITTR HART Smart Ring using manufacturer data: subscription cost, battery life, weight, sizing and sensors. WearableTier does not test devices hands-on.
๐ Key Takeaways:
- โCircul Smart Ring features $0/mo zero-subscription model with 7-day battery life.
- โFITTR HART Smart Ring provides $0/mo zero-subscription model with 7-day battery life.
- โAlways test sizing kits for 24 hours prior to final device selection to guarantee reliable biometric signal tracking.
First smart ring that adapts to fit any finger size automatically
The world's most accurate fitness ring with high comfort and style.
Smart Ring Sensors & Biometric Architecture Guide
An overview of optical PPG sensors, skin temperature thermistors, and signal basics.
๐ Category Matchup Trophies
Lowest list price plus 12 months of app subscription fees (MSRP; retail prices vary).
Based on each manufacturer's published app compatibility.
Circul Smart Ring
Check Price on Amazonโก No monthly subscription fee listed
FITTR HART Smart Ring
Check Price on Amazonโก No monthly subscription fee listed
Interactive Biometric Load & Battery Simulator
Manufacturer battery specifications test rings under ambient laboratory conditions. Adjust your daily wearable sensor profile below to estimate real-world endurance and charge cycle frequency.
Circul Smart Ring
Rated Spec: 7 Days MaxFITTR HART Smart Ring
Rated Spec: 7 Days MaxSensor & Hardware Spec Comparison
Published manufacturer specifications for optical sensors, water resistance, thickness and fees
| Hardware Sensor Metric | Circul Smart Ring | FITTR HART Smart Ring |
|---|---|---|
| Optical PPG LED Array | Red, Green, Infrared | Red, Green, Infrared |
| Skin Temperature Sensor | Check Specs | Listed |
| Sleep Metrics Listed | Sleep Stages, Sleep Pattern Tracking | Sleep Duration, Sleep Stages, HRV |
| Water Resistance Depth | 5ATM / 50m | 50m |
| Chassis Thickness | 2.8mm | 2mm |
| Monthly Software Fee | No Monthly Fees | No Monthly Fees |
Battery life estimates apply an illustrative usage multiplier to each ring's manufacturer-rated battery life. Actual endurance varies with settings, fit, and daily activity.
View Full Technical Specs +
Isolated spec differences and direct hardware deltas
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View Full Technical Specs +
Isolated spec differences and direct hardware deltas
| Feature Delta | Circul Smart Ring | FITTR HART Smart Ring |
|---|---|---|
| MSRP | $129 | $250 |
| Thickness | 2.8mm | 2mm |
| Water Resistance | 5ATM / 50m | 50m |
| Sizing Kit Available | โ No | โ Yes |
Shared Standards (9 Identical Specifications)↓
How the Circul Smart Ring and FITTR HART Smart Ring Compare
The head-to-head matchup between the Circul Smart Ring and the FITTR HART Smart Ring represents two distinct engineering philosophies. The Circul Smart Ring features a Unknown (2.8mm thick, 3g), while the FITTR HART Smart Ring is constructed from Titanium (2mm thick, 3g). Both offer robust environmental sealing (5ATM / 50m vs 50m water resistance).
Per manufacturer battery specifications, the Circul Smart Ring is rated for up to 7 days (with a 60-minute recharge via Charging Case), while the FITTR HART Smart Ring is rated for up to 7 days on a single charge (requiring 60 minutes via USB Cable).
Structured Technical Comparison Matrix
| Spec | Circul Smart Ring | FITTR HART Smart Ring |
|---|---|---|
| Battery Life | Up to 7 Days | Up to 7 Days |
| MSRP & Price Tier | $129 ($$ Tier) | $250 ($$ Tier) |
| Weight | 3g | 3g |
| Outer Shell Material | Unknown | Titanium |
| Charging Method | Charging Case | USB Cable |
Interactive Ecosystem Sync Flowchart
Select your phone OS, fitness watch, and apps. Visualize exactly how data flows from your smart ring to your ecosystem, and highlight broken links.
Sync Flow Map
Virtual Sizing Assistant
Convert your finger circumference to a standard US ring size. Smart ring brands may size differently from jewelers, so confirm with the manufacturer's sizing guide or sizing kit before buying.
Your Standard US Ring Size
Smart ring sizes vary by brand and model. Use this as a starting point and confirm your size with the manufacturer's sizing guide or sizing kit before ordering.
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Alternative Smart Ring Matchups
Frequently Asked Questions
Is Circul Smart Ring better than FITTR HART Smart Ring?
The choice between Circul Smart Ring and FITTR HART Smart Ring depends on your priorities. Circul Smart Ring weighs 3g and costs $129 MSRP with a monthly subscription of $0.00. FITTR HART Smart Ring weighs 3g and costs $250 MSRP with a monthly subscription of $0.00.
How does the battery life compare between Circul Smart Ring and FITTR HART Smart Ring?
Circul Smart Ring offers up to 7 days of battery life, whereas the FITTR HART Smart Ring provides up to 7 days of battery endurance.