Garmin · 2019
Forerunner® 45Size, Dimensions & Wrist Fit
The Garmin Forerunner® 45 sits best on flat wrist widths of about 44–60mm (≈ 11.7–16.0cm wrist circumference). Adjust the slider below to check your wrist.
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The Forerunner® 45 in short
The figures that decide whether this watch suits you, pulled out of the full specification sheet further down.
- Rated for 7 days of use per charge.
- Water rated to 5 ATM.
- 32g on the wrist. Lighter than 86% of the 42mm watches we have weights for.
- 1.04" (26.3 mm) diameter Sunlight-visible, transflective memory-in-pixel (MIP) display.
- chemically strengthened glass case, chemically strengthened glass glass.
Does the Forerunner® 45 fit your wrist?
Drag the slider to your wrist width and see the Forerunner® 45 overlaid at true scale. Lug-to-lug — not case diameter — decides whether a watch overhangs your wrist.
Watch Fit Tool
For sports watches, lug-to-lug (L2L) is what matters most — it decides whether a watch overhangs your wrist. Bulky is fine; overhang is not.
Measure at the point where you wear your watch — typically just below the wrist bone.
Flat width — lay your arm on a table, palm facing up, and measure straight across the top of your wrist with a ruler. Bone to bone; do not follow the curve down the sides.
Around — wrap a tape measure snugly round the wrist. No tape? Wrap a strip of paper, mark the overlap and hold the strip against a ruler.
Width ≠ circumference. They are different numbers — around 170mm is about 64mm across — so set the toggle to whichever one you actually measured before you type it in.
Garmin Forerunner® 45
Case 42.0mm · Lug-to-lug 42.0mm · Thickness 11.4mm · 32g
Balanced Fit
42mm on a 55mm wrist
Comfortably inside the edges of your wrist, and it seats and sits low enough to wear without thinking about it.
On a 55mm wrist the sweet spot is 47–53mm lug to lug. This one is 42mm, so you could go bigger.
Measure where you wear it, just below the wrist bone. Either of these works — the tool converts between them.
- 1. Flat width — arm flat on a table, palm up. Measure straight across the top of the wrist, bone to bone, ignoring the curve down the sides.
- 2. Around — a tape, or a strip of paper marked and held against a ruler, snug the whole way round.
Leather: Attaches at the lugs, so the case back rests on your skin. Thins and softens with wear. Typical figures, not this model’s own.
Show the measurementsHide the measurements
- Across the wrist6.5mm spare each side
Comfortable, with visible skin either side.
- Off the wrist11.4mm off the skin
Normal sports-watch height for a wrist this size. (11.4mm case, back against the skin)
- How it seats~4.0mm under the rim
Seats well, with the case back following most of the wrist.
- Weight on the wrist32g
Light enough to forget you have it on. (0.6g per mm of wrist)
Happy with the fit? Check current availability for the Forerunner® 45.
Check offer2D Dimension Schematics
The Forerunner® 45 drawn to scale — from above, and in profile against the wrist.
- Garmin Forerunner® 4542mm · 11.4mm thick
3D preview
Garmin Forerunner® 45 on a wrist
On an arm sized to your own wrist — the view a product photo never gives you.
Shapes are built from published measurements, not manufacturer 3D models — accurate proportions, generic dial.
Forerunner® 45 battery life
The runtime the manufacturer publishes for everyday use.
- Smartwatch7 days
How the Forerunner® 45 ranks on battery
Against the 296 Garmin watches in our database, ranked on each figure Garmin publishes.
- Everyday use7 days#241 of 285
- GPS tracking13 hours#230 of 267
Forerunner® 45 specifications
The figures that decide a purchase, followed by every line Garmin publishes.
- Battery life
- Smartwatch Mode: Up to 7 days GPS mode: Up to 13 hours
- Display
- 1.04" (26.3 mm) diameter
- Resolution
- 208 x 208 pixels
- Water rating
- 5 ATM
- Glass
- chemically strengthened glass
- Strap
- silicone
- Storage
- 80 hours of activity data
- Charging
- Garmin proprietary plug charger
Full specification sheet
86 published lines across 14 groups, unedited
Overview
- Family
- Garmin
General
- Battery life
- Smartwatch Mode: Up to 7 days GPS mode: Up to 13 hours
- Display Size
- 1.04" (26.3 mm) diameter
- Color display
- Lens Material
- chemically strengthened glass
- Memory/History
- 80 hours of activity data
- Strap material
- silicone
- Charging method
- Garmin proprietary plug charger
- Display resolution
- 208 x 208 pixels
Sensors
- GPS
- GLONASS
- Galileo
- Accelerometer
- Garmin Elevate™ wrist heart rate monitor
Product Info
- Main SKU
- 010-02156-05
- Product ID
- 641121
- Product Name
- Forerunner® 45
- Release Date
- 4/30/2019
- Product Variation
- Black
Clock Features
- Timer
- Stopwatch
- Time/date
- Alarm clock
- GPS Time Sync
- Automatic daylight saving time
Cycling Features
- Speed and cadence sensor support (w/sensor)
- Alerts (triggers alarm when you reach goals including time, distance, heart rate or calories)
Running Features
- Run workouts
- Foot pod capable
- GPS-based distance, time and pace
- Cadence (provides real-time number of steps per minute)
What You'll Love
- Display type
- Sunlight-visible, transflective memory-in-pixel (MIP)
- Water rating
- 5 ATM
- Battery life (smartwatch mode)
- Up to 7 days
Activity Profiles
- Gym
- Cardio, Elliptical Training, Stair Stepping
- Cycling
- Biking, Indoor Biking
- Wellness
- Yoga
- Indoor running
- Treadmill Running, Indoor Track Running
- Outdoor running
- Running
Daily Smart Features
- Calendar
- Connectivity
- Find My Phone
- Find My Watch
- Weather forecasts
- Smart Notifications
- Smartphone compatibility
- iPhone®, Android™
- Controls smartphone music
- Pairs with Garmin Connect™ Mobile
- Connect IQ™ (downloadable watch faces, data fields and apps)
- yes (watch faces only)
Activity Tracking Features
- TrueUp™
- Move IQ™
- Step counter
- Calories burned
- Distance traveled
- Intensity minutes
- Move alerts (displays on device after a period of inactivity)
- Auto goal (learns your activity level and assigns a daily step goal)
Health & Wellness Monitoring
- Sleep
- yes (advanced)
- Fitness age
- yes (in app)
- All-day stress
- Resting heart rate
- Abnormal heart rate alerts
- yes (high and low)
- Relaxation breathing timer
- Body Battery™ energy monitor
- Wrist-based heart rate (constant, every second)
Safety and Tracking Features
- Assistance
- yes (smartphone required)
- Live Event Sharing
- Android™ Only
- Incident Detection during select activities
- yes (smartphone required)
Training, Planning and Analysis Features
- HR zones
- HR alerts
- Manual lap
- HR calories
- Voice alerts
- Physio TrueUp
- VO2 Max (Run)
- Advanced workouts
- Interval training
- GPS speed and distance
- Customizable data pages
- Touch and/or button lock
- Activity history on watch
- Downloadable training plans
- Customizable activity profiles
- Auto Pause® automatic timer halt
- Auto Lap® interval tracking feature
- HR broadcast (broadcasts HR data over ANT+® to paired devices)
Alternatives to the Forerunner® 45
Watches that cover a similar amount of wrist, with the measurements that separate them.
Garmin
fēnix® 7S Pro – Sapphire Solar Edition
- Width
- 42mm
- Thick
- 14.1mm
- Weight
- 58g
%20%E2%80%93%20Standard%20Edition%20%7C%2042%20mm.jpg&w=3840&q=75)
Garmin
epix™ Pro (Gen 2) – Standard Edition | 42 mm
- Width
- 42mm
- Thick
- 14.2mm
- Weight
- 63g
Garmin
fēnix® 7S Pro – Solar Edition
- Width
- 42mm
- Thick
- 14.1mm
- Weight
- 63g
%20%E2%80%93%20Sapphire%20Edition%20%7C%2042%20mm.jpg&w=3840&q=75)
Garmin
epix™ Pro (Gen 2) – Sapphire Edition | 42 mm
- Width
- 42mm
- Thick
- 14.2mm
- Weight
- 63g
Garmin
Approach® S70 - 42 mm
- Width
- 42mm
- Thick
- 12.6mm
- Weight
- 44g
Garmin
Bounce™
- Width
- 42mm
- Thick
- 12.6mm
- Weight
- 37.2g
Forerunner® 45 — Frequently Asked Questions
Will the Garmin Forerunner® 45 fit my wrist?
The Garmin Forerunner® 45 looks balanced on flat wrist widths of roughly 44–60mm (about 11.7–16.0cm circumference). Drag the slider above to check it against your own measurement.
How long does the Garmin Forerunner® 45 battery last?
Garmin rates it at 7 days per charge in everyday use.
How does the Garmin Forerunner® 45 battery compare with other Garmin watches?
At 7 days in everyday use it ranks #241 of the 285 Garmin watches in our database — below the middle of the range. The full ranking, including GPS and power-saving figures, is on our Garmin battery life comparison.
Is the Garmin Forerunner® 45 thick for a 42mm watch?
At 11.4mm, thinner than 74% of 42mm watches, so it slides under a cuff more easily than most of its size. Thickness, not case width, is what decides whether a watch catches on a shirt cuff.
What other watches are the same size as the Garmin Forerunner® 45?
Certina DS Action Chrono PVD / Carbon / Bracelet, Omega Speedmaster Professional Moonwatch 3861 Moonshine Gold / Black Lacquer, TAG Heuer Carrera Chronograph Seafarer Stainless Steel / Silver, Huawei Watch 5 - 42mm all sit within half a millimetre of the Garmin Forerunner® 45's 42mm case, so they cover the same amount of wrist.
