Skip to contentGo to Product Search
Main Content
product image

Samsung - Galaxy Watch4 Aluminum Smartwatch 40mm LTE - Black - (2021)

Rating 4.4 out of 5 stars with 466 reviews

$251.83
The price was $264.42

Samsung - Galaxy Watch4 Aluminum Smartwatch 40mm LTE - Black - (2021)

Model: SM-R865UZKAXAA
SKU: 12189581
$251.83
Save $12.00
The comparable value is $264.42
or
Finance OptionsView your offers
Availability
Fulfillment OptionsShipping selected
FREE shipping to
Sold & shipped by
antonline
(497)

More Buying Options

Specifications
  • Screen Size
    40 millimeters
    Touch Screen
    Yes
    Operating System Compatibility
    Android
    Operating System
    Android
    App Compatible
    Yes
    Carrier
    Unlocked
  • Key Specs
    • Screen Size: 40 millimeters (Size of the screen, measured diagonally from corner to corner.)
    • Touch Screen: true (Touch-screen devices make navigating more intuitive. Using a touch-screen display, you can do things such as tap to select, hold and drag to move items, swipe to scroll, and pinch to zoom.)
    • Operating System Compatibility: Android
    • Operating System: Android (The operating system manages all software and hardware, including files, memory and connected devices. Most importantly, it lets you interact with your device and your programs in a visual way; otherwise, you'd be typing computer code to get anything done.)
    • App Compatible: true (The product can be connected to a program or software application on a mobile device, which then receives collected data from the product.)
    • Carrier: Unlocked
    • Built-in Storage: 16 gigabytes
    • Global Positioning: GLONASS, GPS, Galileo (A system of satellites which enables a mobile receiver to determine its precise location based on signals received from satellites such as the US Global Positioning System (GPS), the Russian Global Navigation Satellite System (GLONASS), the European Global Navigation Satellite System (Galileo), or the Japanese Quasi-Zenith Satellite System (QZSS).)
    • Metrics Measured: Steps taken
    • Protective Qualities: Water resistant, Dust resistant, Shock resistant
    • Maximum Depth of Water Resistance: 164 feet (Measurement of the maximum depth of water in which the product is able to resist some degree of water penetration.)
    • Band Material: Fluoroelastomer
  • General
    • Brand: Samsung
    • Model Number: SM-R865UZKAXAA
    • Product Name: Galaxy Watch4 Aluminum Smartwatch 40mm LTE
    • Color: Black
    • Product Type: Smartwatch
    • Form Factor: Wristwatch (The size, arrangement, and physical configuration of the product.)
    • Model Family: Samsung Galaxy Watch4
    • Year of Release: 2021
  • Design
    • Case Size: 40mm (The diameter or longest measurement of the case.)
    • Case Shape: Round
    • Band Type: Sport Band
    • Band Color: Black
    • Clasp Type: Buckle
    • Rotating Bezel: false (Rotating the bezel controls the various functions of the device.)
  • Dimensions
    • Case Thickness: 0.39 inches
    • Band Width: 0.79 millimeters
    • Product Height: 1.55 inches (The out of box height of the item. Height is measured as the vertical distance from the bottom of the item to the top as it would be primarily used or placed.)
    • Product Width: 1.59 inches (The out of box width of the item. Width is measured as the horizontal distance from one side of the item to the other as it would be primarily used or placed.)
    • Product Weight: 0.9135966 ounces (The out of box weight of the item.)
    • Product Length: 0.38 inches (The out of box length of the item. Length is measured as the longest dimension of the item.)
    • Size: Small
    • Band Size: Adjustable
  • Display
    • Display Screen: true
    • Screen Size: 40 millimeters (Size of the screen, measured diagonally from corner to corner.)
    • Touch Screen: true (Touch-screen devices make navigating more intuitive. Using a touch-screen display, you can do things such as tap to select, hold and drag to move items, swipe to scroll, and pinch to zoom.)
    • Screen Resolution: 396 x 396 (Screens come in a range of resolutions (measured in pixels, horizontal x vertical). The higher the resolution, the greater the picture quality.)
    • Display Type: AMOLED
    • Color Display: true
    • Backlit Display: false (Integrated lights allow for visibility of the display in low-light conditions.)
    • Adjustable Brightness: true
    • Customizable Watch Faces: true
    • Screen Material: Corning Gorilla Glass DX+
  • Compatibility
    • Operating System Compatibility: Android
    • Operating System: Android (The operating system manages all software and hardware, including files, memory and connected devices. Most importantly, it lets you interact with your device and your programs in a visual way; otherwise, you'd be typing computer code to get anything done.)
    • App Compatible: true (The product can be connected to a program or software application on a mobile device, which then receives collected data from the product.)
    • Works With: Google Home, SmartThings (Compatible with or able to be connected to other smart devices or applications.)
    • Voice Assistant Built-in: Bixby, Google Assistant (A digital assistant built into the device that uses voice commands to answer questions and control smart devices.)
  • Connectivity
    • Carrier: Unlocked
    • Bluetooth Version: 5.0 (The Bluetooth specification formalized by the Bluetooth Special Interest Group. All versions of the Bluetooth standard are backwards compatible with previous versions.)
    • Wireless Connectivity: Bluetooth, Wi-Fi (The manner in which a device sends data to another device over a short distance without the use of wires or cables.)
    • Wireless Standard: N (The wireless networking protocol used by the device. Each iteration of the protocol is based on the 802.11 standard developed by the Institute of Electrical and Electronics Engineers (IEEE) Standards Association. Denoted by letters following 802.11 (802.11a, 802.11ac, etc.), each version, published in alphabetical order, encompasses all previous versions.)
  • Features
    • Built-in Storage: 16 gigabytes
    • GPS Enabled: true
    • Global Positioning: GLONASS, GPS, Galileo (A system of satellites which enables a mobile receiver to determine its precise location based on signals received from satellites such as the US Global Positioning System (GPS), the Russian Global Navigation Satellite System (GLONASS), the European Global Navigation Satellite System (Galileo), or the Japanese Quasi-Zenith Satellite System (QZSS).)
    • Mobile Notifications: true
    • Alert Type: Audible, Vibration, Visual
    • Mobile Payment Service Supported: Samsung Pay, Google Pay
    • Music Player: true
    • Silent Alarm: true
    • Built-In Microphone: true
    • Voice Activated: true (Able to interpret dictation and/or respond to simple voice commands.)
  • Activity
    • Metrics Measured: Steps taken
    • Sensors: Accelerometer, Barometer, Gyro sensor, Geomagnetic sensor, Ambient light sensor, Optical heart rate (PPG) sensor, Electrical heart rate (ECG) sensor (Detects stimuli such as heat, light, sound, motion, or pressure and responds accordingly by operating a control or initiating a function of the device.)
    • Medical Incident Notification: 911/EMS, App alert, Contact call, Contact text (Receive notifications for detected medical incidents that enable you to contact emergency services if needed. In some cases, emergency services and/or preprogrammed emergency contacts may be notified automatically. May be reliant on whether wireless network coverage is available.)
  • Performance
    • Protective Qualities: Water resistant, Dust resistant, Shock resistant
    • Maximum Depth of Water Resistance: 164 feet (Measurement of the maximum depth of water in which the product is able to resist some degree of water penetration.)
    • Maximum Height of Shock Resistance: 4.92 feet (Maximum height from which the product can be dropped and resist some degree of damage from impact.)
    • Ingress Protection (IP) Rating: IP68 (A 4 to 6 character code classifying a product's degree of protection against intrusion of solid particles and liquids as well as impact. Each number in the IP Code denotes a level of protection, determined through testing and published by the International Electrotechnical Commission (IEC). The first digit represents the degree of protection against solid foreign objects or particles and the second digit represents the degree of protection against water ingress.)
    • Minimum Operating Temperature: 32 degrees fahrenheit (The lowest recommended ambient (surrounding) temperature in which the product can ideally operate stated by the manufacturer. Generally long-term exposure of the product to temperatures less than the minimum can result in ineffective operation.)
    • Maximum Operating Temperature: 95 degrees fahrenheit (The highest recommended ambient (surrounding) temperature in which the product can ideally operate stated by the manufacturer. Generally long-term exposure of the product to temperatures more than the maximum can result in ineffective operation.)
  • Processor
    • Processor Speed: 1.18 gigahertz (Actual central processing unit (CPU) speed may vary by device configuration and design. Also referred to as clock speed, this is how quickly the central processing unit (CPU) can receive and interpret instructions. The higher the number, the more operations per second that can be completed. Working in combination with system memory, the power of the processor determines the complexity of software you can run.)
    • Central Processing Unit: Exynos W920 Dual Core 1.18GHz
  • Power
    • Rechargeable: true
    • Battery Strength Indicator: true
    • Battery Capacity: 247 milliampere hours (The amount of energy stored in the battery.)
    • Charging Time: 110 minutes
    • Charging Interface(s): Wireless (The connection for transmitting power to charge the device.)
    • Battery Chemistry: Lithium-ion
    • Replaceable Battery: false
  • Material
    • Band Material: Fluoroelastomer
    • Case Material: Aluminum
    • Case Back Material: Aluminum
  • Camera
    • Integrated Camera: No
  • Warranty
    • Warranty - Parts: 1 year
    • Warranty - Labor: 1 year
  • Other
    • UPC: 887276550282

Crush workouts and all your health goals with Samsung Galaxy Watch4. Be your best with the watch that knows you best.

  • Body Composition Analysis: Get ready to crush your wellness goals with body readings right on your wrist.
  • Advanced Sleep / Continuous SpO2: Manage your overall sleep quality for a great night's sleep with an advanced tracker that calculates your sleep score.
  • ECG: Be smart about your heart with ECG Monitoring that gives accurate readings.
  • Fitness / Auto Workout Tracking: Make the most of every workout with Auto Workout Tracking. Stay motivated by connecting to live coaching sessions via your smartphone or to dynamic Group Challenges with your friends.
  • V02 Max / Advanced Run Coaching: Make the most out of every mile with Advanced Run Coaching and VO2 max readings to assess your cardio levels.
  • Extension of Your Phone: Stay in stride while staying connected to calls, text and music on the go.
  • Upgraded OS (GSuiteApps): Tap into the power and convenience of select Google services and apps on your wrist.
  • LTE Connectivity: No phone or Wi-Fi? No problem. Stay connected wherever your workout takes you, thanks to LTE connectivity.
  • Sleek and Lightweight Design: Look great while crushing every part of your day with the sleek, lightweight and customizable design.
  • Group Challenges: Get moving and motivated with your family and friends. Join the fitness fun with activities and challenges designed just for groups.
  • Trip Detection: Get peace of mind while on the go with Trip Detection that sends an SOS to your emergency contact in the event of a hard fall.
  • Women’s Health: Galaxy Watch4 helps women build a deeper connection with their bodies and their health by helping to log and track fertility windows, ovulation cycles and periods.
  • Samsung Health: Samsung Health helps you stay on top of your health, your goals and upcoming fitness needs.
  • Payments: Tap. Pay. Go. Samsung Pay and Google Pay make quick stops even quicker.
  • SmartThings: Cool down the house as you cool down from your workout with a tap of your wrist.
  • Ecosystem: Breeze through your fitness goals by pairing your compatible Galaxy devices and by connecting to your fitness community.
  • Body Composition Analysis: Get ready to crush your wellness goals with body readings right on your wrist.
  • Advanced Sleep / Continuous SpO2: Manage your overall sleep quality for a great night's sleep with an advanced tracker that calculates your sleep score.
  • ECG: Be smart about your heart with ECG Monitoring that gives accurate readings.
  • Fitness / Auto Workout Tracking: Make the most of every workout with Auto Workout Tracking. Stay motivated by connecting to live coaching sessions via your smartphone or to dynamic Group Challenges with your friends.
  • V02 Max / Advanced Run Coaching: Make the most out of every mile with Advanced Run Coaching and VO2 max readings to assess your cardio levels.
  • Extension of Your Phone: Stay in stride while staying connected to calls, text and music on the go.
  • Upgraded OS (GSuiteApps): Tap into the power and convenience of select Google services and apps on your wrist.
  • LTE Connectivity: No phone or Wi-Fi? No problem. Stay connected wherever your workout takes you, thanks to LTE connectivity.
  • Sleek and Lightweight Design: Look great while crushing every part of your day with the sleek, lightweight and customizable design.
  • Group Challenges: Get moving and motivated with your family and friends. Join the fitness fun with activities and challenges designed just for groups.
  • Trip Detection: Get peace of mind while on the go with Trip Detection that sends an SOS to your emergency contact in the event of a hard fall.
  • Women’s Health: Galaxy Watch4 helps women build a deeper connection with their bodies and their health by helping to log and track fertility windows, ovulation cycles and periods.
  • Samsung Health: Samsung Health helps you stay on top of your health, your goals and upcoming fitness needs.
  • Payments: Tap. Pay. Go. Samsung Pay and Google Pay make quick stops even quicker.
  • SmartThings: Cool down the house as you cool down from your workout with a tap of your wrist.
  • Ecosystem: Breeze through your fitness goals by pairing your compatible Galaxy devices and by connecting to your fitness community.
Whats Included
  • Device
  • Wireless Charger
  • Quick Start Guide
  • Device
  • Wireless Charger
  • Quick Start Guide

Q: new to smart watches, what is the difference between the choices "unlocked" or GPS?

A: That is a great question, Traci! The Unlocked means that you are able to add services through your carrier to use all of the features without your phone being present. If it is described as Bluetooth or GPS, it means that the mobile device needs to stay within range for all features to be used. Thank you for taking the time to ask this question. ^Kayla

Q: C an you answer calls on it

A: If you buy the watch with its own plan through your carrier. I have Verizon so we added it to our mobile plan for 9.99 month. That way you can use the watch without having your phone with you. Great for going on a run or if your phone dies you still have watch as an option. It will ring when you have a phone call even if your phone is not with you.

Q: So, battery life is missing from the specs. I'm guessing it's not great? I can't find it here, or on Samsung's site for the 40MM LTE version. Anyone?

A: Battery life is the worst. I previously had the Watch Active 2 and could go approximately 1-2 days before having to charge it again. It’s only 2 months old and the battery life gets worse every day. I literally charged this watch 10 hours ago and just had to put it on the charger because the battery was low.

Q: In this LTE won't work as BT ? If doesn't have service won't work at all ?

A: It works just fine without cellular service. Just no long runs without taking my phone for Spotify. But you can download music into the watch it self.

Q: Is this watch compatible with a Samsung Galaxy S10e?

A: Hi MichaelS! Thank you for reaching out to us. We appreciate your interest in knowing if Galaxy Watch4 is compatible with Samsung Galaxy S10e. To answer your question, yes, Galaxy Watch4 is compatible with Galaxy S10e. For more information, you can visit this link about Samsung smartwatch and phone compatibility: https://www.samsung.com/us/support/answer/ANS00082502/. Should you need more assistance, please feel free to get back to us via the following options: 1. Facebook Messenger: http://m.me/samsungsupport 2. Twitter: https://twitter.com/messages/compose?recipient_id=18768513 3. Samsung Community: https://us.community.samsung.com/t5/Samsung-Community/ct-p/us Reference #: 1144215444 Have a great day. Melardo

Q: What does LTE mean?

A: The LTE is long term evolution, it just means it has a cellular chip in it for stand alone phone calls ad web service.

Q: If I give this to my son (whom does not have a phone) can he use it to call and text people? Do I set him up with his own plan so he gets his own "number" or would he be under my plan and my phone number?

A: You would need to set up the watch with its own data plan if your son does not have a phone. But yes, he would be able to call and text with it

Q: CAN YOU CHANGE OUT THE BAND

A: Yes u can as long as its the correct size. Can also use standard regular watch bands.

Sponsored

Compare similar products

Samsung - Galaxy Watch4 Aluminum Smartwatch 40mm LTE - Black - (2021)
Samsung - Galaxy Watch4 Aluminum Smartwatch 40mm LTE - Black - (2021)

Crush workouts and all your health goals with Samsung Galaxy Watch4. Be your best with the watch that knows you best.

Samsung - Galaxy Watch7 Aluminum Smartwatch 40mm BT - Cream - (2024)

Your favorite new health and wellness companion is here — Galaxy Watch7. Enhanced with Galaxy AI,¹ this Watch has everything you need to keep you moving toward your health goals. Wake up on the right side of the bed every morning with an Energy Score1 that helps you understand your well-being better. Hit your morning workout while staying in touch with your world — make calls from your Watch and quickly respond to texts on the go with Suggested Replies.² Then hone in on your heart health during your workout with improved Heart Rate Tracking,³ and improve each day with personalized Wellness Tips⁴ viewable right on your Galaxy smartphone.⁵ Plus, stay in the zone by streaming your favorite playlist or podcast from your Watch to your Galaxy Buds.⁶ Your ultimate fitness partner is now on your wrist — Galaxy Watch7.

Samsung - Galaxy Watch7 Aluminum Smartwatch 44mm BT - Green - (2024)

Your favorite new health and wellness companion is here — Galaxy Watch7. Enhanced with Galaxy AI,¹ this Watch has everything you need to keep you moving toward your health goals. Wake up on the right side of the bed every morning with an Energy Score1 that helps you understand your well-being better. Hit your morning workout while staying in touch with your world — make calls from your Watch and quickly respond to texts on the go with Suggested Replies.² Then hone in on your heart health during your workout with improved Heart Rate Tracking,³ and improve each day with personalized Wellness Tips⁴ viewable right on your Galaxy smartphone.⁵ Plus, stay in the zone by streaming your favorite playlist or podcast from your Watch to your Galaxy Buds.⁶ Your ultimate fitness partner is now on your wrist — Galaxy Watch7.

Samsung - Galaxy Watch8 Aluminum Smartwatch 40mm BT - Silver - (2025)

Galaxy Watch8 is built for those who never settle when it comes to self improvement. With a sporty yet sleek design, it packs a serious punch of enhanced performance, longer battery life and smart health tracking to keep you locked into your health and wellness goals, wherever they may take you. Your Watch8 works around the clock because a healthy lifestyle starts with healthy sleep. Advanced Sleep Tracking doesn’t just log hours, but it also takes a closer look at everything that happened while you snoozed. Wake up feeling lethargic? Get a full report on your sleep behavior, environment and disruptions, such as snoring. And when it’s time to get back on your feet for a new day and a new workout, you’re equipped with the insights you need to stay motivated with Energy Score. Need to multitask during your workout? Simply raise your wrist and speak naturally to send a text to meet up with a friend later, set a timer for your next mile or pull up your past run times. Watch8 is powerful and features an improved battery built to keep up with your longest bike rides without weighing you down. Thanks to a thinner, lighter body and dynamic strap system that molds to your wrist, you’ll almost forget your Watch is there as it tracks even the most intense workouts. Plus, the bright screen is visible even when you have to hit the trail in full sun. Galaxy Watch8 is more than a watch it’s a health coach and tracker that fits your wrist and your lifestyle.

Pros for Samsung - Galaxy Watch4 Aluminum Smartwatch 40mm LTE - Black - (2021)
There were no pros for this productOverall Performance, Features, Design, Ease of Use, Health TrackingThere were no pros for this productOverall Performance, Features, Design, Battery Life, Comfort
Cons for Samsung - Galaxy Watch4 Aluminum Smartwatch 40mm LTE - Black - (2021)
There were no cons for this productBattery Life, Band ComfortThere were no cons for this productBand Size, Connectivity

Specs

Reviews

Customer Images

The vast majority of our reviews come from verified purchases. Reviews from customers may include My Best Buy members, employees, and Tech Insider Network members (as tagged). Select reviewers may receive discounted products, promotional considerations or entries into drawings for honest, helpful reviews.

  • Rated 5 out of 5 stars

    It's a great watch!

    I was very hesitant about buying this watch due to the bad reviews about the battery life or the bezel not rotating or the ECG not working. HAPPY to say I've not had any problems with this watch! It's goes perfectly with my Galaxy S21. It's super easy to set up and use! I upgraded from the original Galaxy watch and this one is much lighter and smaller.

    This review is from Samsung - Galaxy Watch4 Aluminum Smartwatch 40mm LTE - Gold - (2021)

    BBGirl Posted

  • Rated 4 out of 5 stars

    Almost great

    Good but has its problems. Can be glitchy at times. Has time when it will start showing im running and im sitting down watching tv. Great overall watch tho, love thr connection features, especially the find my phone app lol. Not a terrible watch just has its issues. Make sure to put the watch on rain mode when in water. The watch can be very sensitive at times when water runs across the face of the watch.

    This review is from Samsung - Galaxy Watch4 Aluminum Smartwatch 40mm LTE - Gold - (2021)

    Rickbobby252 Posted

  • Rated 4 out of 5 stars

    New Galaxy watch 4 to replace Active 2

    I upgraded from my Active 2 when it died. The watch seems good so far. I am used to the swipe/screens on my old watch, so this one is taking some getting used to. I am only using as a Bluetooth connection so far, which is what my last watch was...but like that I can switch to LTE when ready. Though it is the same 40mm size as my Active 2, it seem a bit bigger on my wrist.

    This review is from Samsung - Galaxy Watch4 Aluminum Smartwatch 40mm LTE - Gold - (2021)

    StephanieW Posted

No content
Sponsored

Similar products from outside of Best Buy

sponsored

Finance Options

My Best Buy® Credit Card
10% back in rewardson your first day of purchases when approved for the My Best Buy® Credit Card.
Buy Now, Pay Later
4 payments starting at $62.96
Lease to own
Apply today with no credit needed and enjoy flexible payment options.