| Case diameter | 36–40 mm for a compact fit; 40–44 mm for a larger display | Smaller cases generally fit narrow wrists more comfortably and reduce snagging on clothing. | Measure wrist circumference before purchase. A 14–16 cm wrist usually benefits from a compact case, subject to lug design. | High priority |
| Weight and thickness | Preferably under 40 g excluding the strap and approximately 10–12 mm thick | Lower weight can improve comfort during sleep, exercise, commuting, and extended daily wear. | Compare the listed weight without the strap; metal cases and larger batteries normally increase weight. | High priority |
| Strap flexibility | Soft silicone, fluoroelastomer, fabric, or leather options with multiple adjustment holes | A flexible strap helps accommodate smaller wrists and changes in wrist comfort during heat or exercise. | Check strap width, replacement availability, and whether standard spring-bar or proprietary connectors are used. | High priority |
| Android compatibility | Native Android support with a clearly stated minimum Android version | Reliable notifications, calls, health synchronization, and app installation depend on phone compatibility. | Operating-system requirements vary by watch and region. Confirm support for the exact phone model before buying. | Essential |
| Battery endurance | At least 24 hours with smart features enabled; 2–7 days for fitness-focused designs | Longer endurance supports continuous activity, sleep, and cycle tracking with fewer charging interruptions. | Always compare manufacturer estimates under the same conditions; GPS, LTE, display brightness, and health sensors reduce runtime. | Essential |
| Water resistance | At least 5 ATM for regular water exposure, when the manufacturer permits it | Useful for workouts, rain, hand washing, and swimming-related activities. | 5 ATM represents laboratory pressure resistance and does not mean the watch can be used at a 50-metre diving depth. Avoid hot showers and high-pressure water unless approved. | High priority |
| Health and wellness sensors | Optical heart-rate monitoring, sleep tracking, blood-oxygen estimation, skin-temperature trends, and menstrual-cycle logging | These features can support wellness awareness and personal trend tracking. | Feature availability and accuracy vary by device, skin contact, activity, software, and country. Wellness readings are not medical diagnoses. | High priority |
| Cycle and pregnancy tools | Manual cycle logging with optional temperature-based trend information | Provides convenient personal records without assuming that every user has the same cycle pattern. | Check privacy controls, export options, data retention, and local availability. Do not use watch predictions as contraception or medical advice. | Important |
| Display readability | AMOLED or equivalent high-contrast display with adjustable brightness and a compact-width layout | A clear display improves readability for notifications, workouts, and navigation without requiring a large case. | Check outdoor brightness, automatic brightness, text-size controls, and support for the buyer’s language. | High priority |
| GPS and workout tracking | Built-in multi-constellation GNSS for outdoor exercise without carrying a phone | Supports walking, running, cycling, and travel tracking while improving independence from the smartphone. | GPS accuracy depends on buildings, trees, weather, satellite conditions, and software. Confirm supported sports and map features. | Important |
| Safety and communication | Emergency contact functions, fall detection where available, location sharing, and optional cellular connectivity | Can provide an additional communication option during exercise, commuting, or travel. | Emergency services, cellular plans, fall detection, and location features vary by country, carrier, age, and local regulations. | Important |
| Privacy and regional availability | Clear permission controls, encrypted account access, data deletion, and local service support | Health and location data are sensitive, so control over collection and sharing is essential. | Review the privacy policy, warranty region, app-store availability, payment functions, language support, and repair options before purchase. | Essential |