10 Best 40mm Smartwatches Of 2026
40mm Smartwatches — Reviews, Recommendations & Updated Buying Guide September 2026
![Samsung Galaxy FIT 3 [2024] 1.6"](https://m.media-amazon.com/images/I/61K2qby-3oL._AC_UL320_.jpg)
Samsung Galaxy FIT 3 [2024] 1.6"
おすすめの理由
![Samsung Galaxy FIT 3 [2024] 1.6"](https://m.media-amazon.com/images/I/61Wm+hvw0ML._AC_UL320_.jpg)
Samsung Galaxy FIT 3 [2024] 1.6"
おすすめの理由
Samsung Galaxy Watch 8 (2025) 40mm
おすすめの理由
Apple Watch SE 3 GPS 40mm
おすすめの理由
Samsung Galaxy Watch7 Smartwatch
おすすめの理由
Samsung Galaxy Watch7 Smartwatch
おすすめの理由
SAMSUNG Galaxy Watch7 Smartwatch
おすすめの理由
クイックピック
10 Best 40mm Smartwatches Of 2026
クイックピック
Samsung Galaxy FIT 3 [2024] 1.6" AMOLED Display | 13 Days Battery Life | 100+ Watchfaces | 100+ Exercise Modes | CAD Version & Warranty - (Black)
Apple Watch SE 3 GPS 40mm Smartwatch with Starlight Aluminium Case with Starlight Sport Band S/M. Fitness and Sleep Trackers, Heart Rate Monitor, Always-On Display, Water Resistant
Samsung Galaxy FIT 3 [2024] 1.6" AMOLED Display | 13 Days Battery Life | 100+ Watchfaces | 100+ Exercise Modes | CAD Version & Warranty - (Pink Gold)
Samsung Galaxy Watch 8 (2025) 40mm Bluetooth Smartwatch, Cushion Design, Fitness Tracker, Sleep Coaching, Running Coach, Energy Score, Heart Rate Tracking, Graphite [US Version, 2 Yr Warranty]
Apple Watch SE 3 GPS 40mm Smartwatch with Midnight Aluminium Case with Midnight Sport Band S/M. Fitness and Sleep Trackers, Heart Rate Monitor, Always-On Display, Water Resistant
Samsung Galaxy Watch7 Smartwatch, Cream, 40mm, Bluetooth, Sleep Coaching, Fitness Tracker (UAE Version)
Samsung Galaxy Watch7 Smartwatch, Cream, 40mm, LTE, Sleep Coaching, Fitness Tracker (UAE Version)
![Samsung Galaxy Watch9, Graphite, 40mm Bluetooth Smartwatch | AI Assistant, Fitness Tracker, Sleep Coaching and Running Coaching with Heart Rate Tracking [US Version, 2 Yr Warranty]](https://m.media-amazon.com/images/I/61gMNpGYJkL._AC_UY218_.jpg)
Samsung Galaxy Watch9, Graphite, 40mm Bluetooth Smartwatch | AI Assistant, Fitness Tracker, Sleep Coaching and Running Coaching with Heart Rate Tracking [US Version, 2 Yr Warranty]
SAMSUNG Galaxy Watch7 Smartwatch Bluetooth 40mm Cream
Smart Watch, 1.85"Smartwatch for Men Women (Answer/Make Call), Fitness Tracker with 140+Sport Modes, IP68Waterproof, HeartRate/Sleep/Spo2Monitor, Pedometer, ActivityTracker for Android iOS Starlight
購入ガイド: 40mm Smartwatches
📋 目次
1What battery life should I look for in a 40mm smartwatch?
Aim for at least 3-5 days of battery life on a single charge. Smaller 40mm watches often have smaller batteries, so models with efficient processors and low-power displays (like AMOLED with adaptive brightness) will last longer between charges.
2Does screen size affect the usability of a 40mm smartwatch?
Yes — 40mm is ideal for smaller wrists and offers a good balance between readability and portability. However, it may limit the amount of information displayed at once, so look for models with high-resolution screens and swipe gestures for easy navigation.
3What health tracking features are worth prioritizing?
Heart rate monitoring, sleep tracking, and blood oxygen (SpO2) sensors are standard and valuable. Advanced features like ECG, stress monitoring, or menstrual cycle tracking can be worth paying more for, depending on your health goals and usage patterns.
4Are 40mm smartwatches suitable for swimming or water activities?
Some models are water-resistant up to 50 meters (5ATM), making them suitable for swimming and light water exposure. Check for IP68 or 5ATM ratings, and avoid submerging the watch if it’s not explicitly rated for water sports or swimming.
5What should I consider when choosing a 40mm smartwatch for fitness tracking?
Look for models with built-in GPS for accurate outdoor tracking, a variety of workout modes, and compatibility with popular fitness apps. A 40mm size works well for running or gym use, but ensure the watch has a secure fit and a durable, sweat-resistant build.
選び方について
編集者は製品を試し、それについて書くことを心から愛するメンバーです。各製品の実際の使いやすさと強みを比較し、最も重要な点を独自の「おすすめの理由」にまとめています。購入前に、大切なポイントがひと目でわかります。