Garmin
Instinct® E – 40 mm vs Instinct® E – 45 mm
Size, specs & wrist fit compared
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Which one fits you
On wrists narrower than about 47mm, the Instinct® E – 40 mm is the safer pick — it stays proportionate down to roughly 42mm, where the Instinct® E – 45 mm starts to hang over the edge. Above 47mm both sit cleanly, and the Instinct® E – 45 mm gives you more presence.
The Instinct® E – 45 mm wears larger than the Instinct® E – 40 mm (45mm vs 40mm case), giving it more wrist presence — and needing a wider wrist to sit cleanly.
The Instinct® E – 40 mm is the slimmer of the two (13.6mm vs 14.2mm), so it slides under a cuff more easily.
On the wrist the Instinct® E – 40 mm feels lighter (41g vs 48g, case only).
The Instinct® E – 40 mm is thicker than 98% of the 40mm watches we track and the Instinct® E – 45 mm than 68% of the 45mm ones — so both sit higher than their widths suggest.
The Instinct® E – 45 mm is 5mm wider, 5mm longer, 0.6mm thicker and 7g heavier than the Instinct® E – 40 mm. Both are circular.
Instinct® E – 40 mm
Instinct® E – 45 mm
Case width
40mm
45mm+5mm
Lug-to-lug
40mm
45mm+5mm
Thickness
13.6mm
14.2mm+0.6mm
Weight
41g
48g+7g
Switch or add watches
Garmin
Instinct® E – 40 mm
Garmin
Instinct® E – 45 mm
2D Dimension Schematics
Every case drawn to scale on a shared centre — from above, and in profile against the wrist.
Highlight
- Garmin Instinct® E – 40 mm40mm · 13.6mm thick
- Garmin Instinct® E – 45 mm45mm · 14.2mm thick
3D preview
Instinct® E – 40 mm vs Instinct® E – 45 mm on a wrist
Sized to your own wrist, turned any way you like.
Shapes are built from published measurements, not manufacturer 3D models — accurate proportions, generic dial.
Battery life compared
Runtime for every power mode either watch publishes, 1 of them directly comparable.
40 mm45 mm
Smartwatch
14 days16 days
Specifications
The short version
7 key specs| Spec | GarminInstinct® E – 40 mm | GarminInstinct® E – 45 mm |
|---|---|---|
| Case Width | 40mm | 45mm |
| Thickness | 13.6mm | 14.2mm |
| Weight | 41g | 48g |
| Shape | Circular | Circular |
| Display type | Monochrome, sunlight-visible, transflective memory-in-pixel (MIP) | Monochrome, sunlight-visible, transflective memory-in-pixel (MIP) |
| Battery life | Smartwatch: Up to 14 days Battery Saver Watch Mode: Up to 35 days GPS: Up to 21 hours All Satellite Systems: 14 hours Max Battery GPS Mode: Up to 43 hours Expedition GPS Activity: Up to 17 days | Smartwatch: Up to 16 days Battery Saver Watch Mode: Up to 40 days GPS: Up to 24 hours All Satellite Systems:16 hours Max Battery GPS Mode: Up to 50 hours Expedition GPS Activity: Up to 20 days |
| Released | 2025 | 2025 |
Every specification
204 specs| Spec | Garmin Instinct® E – 40 mm | Garmin Instinct® E – 45 mm |
|---|---|---|
| Overview | ||
| Family | Garmin | Garmin |
| General | ||
| Timer | Yes | Yes |
| Stopwatch | Yes | Yes |
| Time/date | Yes | Yes |
| Alarm clock | Yes | Yes |
| Display type | Monochrome, sunlight-visible, transflective memory-in-pixel (MIP) | Monochrome, sunlight-visible, transflective memory-in-pixel (MIP) |
| Water rating | 10 ATM | 10 ATM |
| GPS Time Sync | Yes | Yes |
| Sunrise/sunset times | Yes | Yes |
| Pulse Ox blood oxygen | Yes | Yes |
| Sleep score and insights | Yes | Yes |
| Automatic daylight saving time | Yes | Yes |
| Battery life (smartwatch mode) | Up to 14 days | Up to 16 days |
| Sensors | ||
| Stocks | Yes | Yes |
| Calendar | Yes | Yes |
| Passcode | Yes | Yes |
| Connectivity | Bluetooth®, ANT+® | Bluetooth®, ANT+® |
| Garmin Share | Yes | Yes |
| Find My Phone | Yes | Yes |
| Morning report | Yes | Yes |
| Weather forecasts | Yes | Yes |
| Smart Notifications | Yes | Yes |
| Smartphone compatibility | iPhone®, Android™ | iPhone®, Android™ |
| Controls smartphone music | Yes | Yes |
| On-device Connect IQ™ Store | Yes | Yes |
| Pairs with Garmin Connect™ mobile | Yes | Yes |
| Find My Garmin (helps locate lost device) | Yes | Yes |
| Battery saver (customizable low power watch) | Yes | Yes |
| Realtime settings sync with Garmin Connect™ mobile | Yes | Yes |
| Text response/reject phone call with text (Android™ only) | Yes | Yes |
| Connect IQ™ (downloadable watch faces, data fields and apps) | Yes | Yes |
| Variant | ||
| Color | Black with Charcoal Band | Black with Charcoal Band |
| Version | Instinct E | Instinct E |
| Case Size | 40 mm | 45 mm |
| Solar Charging | No | No |
| Available Colors | — | Black with Charcoal Band; Electric Lime with Electric Lime Band |
| Product Info | ||
| Price | 249.99 USD | 249.99 USD |
| Sale Price | 199.99 USD | 199.99 USD |
| Clock Features | ||
| Sleep | yes (advanced) | yes (advanced) |
| Hydration | yes (in Garmin Connect™ and optional Connect IQ™ widget) | yes (in Garmin Connect™ and optional Connect IQ™ widget) |
| Breathwork | Yes | Yes |
| Fitness age | Yes | Yes |
| Health status | Yes | Yes |
| Nap detection | Yes | Yes |
| All-day stress | Yes | Yes |
| Women's health | yes (in Garmin Connect™ and optional Connect IQ™ widget) | yes (in Garmin Connect™ and optional Connect IQ™ widget) |
| Health snapshot | Yes | Yes |
| Respiration rate | Yes | Yes |
| Resting heart rate | Yes | Yes |
| Breathing variations | Yes | Yes |
| Relaxation reminders | Yes | Yes |
| Abnormal heart rate alerts | yes (high and low) | yes (high and low) |
| Relaxation breathing timer | Yes | Yes |
| Body Battery™ energy monitor | Yes | Yes |
| Heart rate (constant, every second) | Yes | Yes |
| Cycling Features | ||
| Pool swim workouts | Yes | Yes |
| Time and distance alerts | Yes | Yes |
| Auto rest (pool swim only) | Yes | Yes |
| Drill logging (pool swim only) | Yes | Yes |
| Countdown start (pool swim only) | Yes | Yes |
| Underwater wrist-based heart rate | Yes | Yes |
| "Repeat on" rest timer (pool swim only) | Yes | Yes |
| Basic rest timer (up from 0) (pool swim only) | Yes | Yes |
| Stroke type detection (freestyle, backstroke, breaststroke, butterfly) (pool swim only) | Yes | Yes |
| Pool swim metrics (lengths, distance, pace, stroke count, swim efficiency (SWOLF), calories) | Yes | Yes |
| Open-water swim metrics (distance, pace, stroke count/rate, stroke distance, swim efficiency (SWOLF), calories) | Yes | Yes |
| Running Features | ||
| Tides | Yes | Yes |
| Sight 'N Go | Yes | Yes |
| Tide glance | Yes | Yes |
| UltraTrac mode | Yes | Yes |
| Vertical speed | Yes | Yes |
| GPS coordinates | Yes | Yes |
| Area calculation | Yes | Yes |
| Elevation profile | Yes | Yes |
| Projected waypoint | Yes | Yes |
| Total ascent/descent | Yes | Yes |
| Future elevation plot | Yes | Yes |
| Distance to destination | Yes | Yes |
| Expedition GPS Activity | Yes | Yes |
| Sun and moon information | Yes | Yes |
| Barometric trend indicator with storm alert | Yes | Yes |
| What You'll Love | ||
| Weight | 41 g | 48 g |
| Battery life | Smartwatch: Up to 14 days Battery Saver Watch Mode: Up to 35 days GPS: Up to 21 hours All Satellite Systems: 14 hours Max Battery GPS Mode: Up to 43 hours Expedition GPS Activity: Up to 17 days | Smartwatch: Up to 16 days Battery Saver Watch Mode: Up to 40 days GPS: Up to 24 hours All Satellite Systems:16 hours Max Battery GPS Mode: Up to 50 hours Expedition GPS Activity: Up to 20 days |
| Battery type | Lithium ion | Lithium ion |
| Display Size | custom, two-window design; 0.86” x 0.86” (22 x 22 mm) | custom, two-window design; 0.9” x 0.9” (23 x 23 mm) |
| Case material | fiber-reinforced polymer | fiber-reinforced polymer |
| Lens material | Chemically Strengthened Glass | Chemically Strengthened Glass |
| Physical size | 40 x 40 x 13.6 mm Fits wrists with a circumference of 107-179 mm | 45 x 45 x 14.2 mm Fits wrists with a circumference of 132-213 mm |
| Bezel material | fiber-reinforced polymer | fiber-reinforced polymer |
| Memory/History | 128 MB | 128 MB |
| Strap material | silicone | silicone |
| Charging method | Garmin proprietary plug charger | Garmin proprietary plug charger |
| Display resolution | 166 x 166 pixels (active area) | 176 x 176 pixels |
| QuickFit® watch band compatible | yes (20 mm) | yes (22 mm) |
| Activity Profiles | ||
| Assistance | Yes | Yes |
| Live event sharing | Yes | Yes |
| Incident detection during select activities | Yes | Yes |
| Incident detection alert on phone for wearables | Yes | Yes |
| Tactical Features | ||
| TrueUp™ | Yes | Yes |
| Move IQ™ | Yes | Yes |
| Step counter | Yes | Yes |
| Floors climbed | Yes | Yes |
| Calories burned | Yes | Yes |
| Distance traveled | Yes | Yes |
| Intensity minutes | Yes | Yes |
| Automatic rep counting | Yes | Yes |
| Garmin Connect™ Challenges app | yes (optional Connect IQ app) | yes (optional Connect IQ app) |
| Move alerts (displays on device after a period of inactivity) | Yes | Yes |
| Auto goal (learns your activity level and assigns a daily step goal) | Yes | Yes |
| Outdoor Recreation | ||
| TracBack® | Yes | Yes |
| Back to start | Yes | Yes |
| Reference point | Yes | Yes |
| Point-to-point navigation | Yes | Yes |
| Bread crumb trail in real time | Yes | Yes |
| Daily Smart Features | ||
| HIIT workouts | Yes | Yes |
| Yoga workouts | Yes | Yes |
| Cardio workouts | Yes | Yes |
| Pilates workouts | Yes | Yes |
| Strength workouts | Yes | Yes |
| Garmin running coach experts | Yes | Yes |
| Garmin Coach - Prebuilt cycling plans | Yes | Yes |
| Daily suggested workout - Cycling (pace and heart rate based) | Yes | Yes |
| Daily suggested workout - Running (pace and heart rate based) | Yes | Yes |
| Mapping & Navigation | ||
| Courses | Yes | Yes |
| Race an activity | Yes | Yes |
| Compatible with Varia™ lights | Yes | Yes |
| Speed and cadence sensor support (w/sensor) | Yes | Yes |
| Alerts (triggers alarm when you reach goals including time, distance, heart rate or calories) | Yes | Yes |
| Activity Tracking Features | ||
| % HRR | Yes | Yes |
| % HR max | Yes | Yes |
| HR zones | Yes | Yes |
| HR alerts | Yes | Yes |
| Shortcuts | Yes | Yes |
| HRV status | Yes | Yes |
| Manual lap | Yes | Yes |
| Rest timer | Yes | Yes |
| Auto max HR | Yes | Yes |
| Auto scroll | Yes | Yes |
| Finish time | Yes | Yes |
| HR calories | Yes | Yes |
| Voice alerts | Yes | Yes |
| Custom alerts | Yes | Yes |
| Physio TrueUp | Yes | Yes |
| Recovery time | Yes | Yes |
| VO2 Max (run) | Yes | Yes |
| Course guidance | Yes | Yes |
| Training effect | Yes | Yes |
| Virtual Partner | Yes | Yes |
| Workout benefit | Yes | Yes |
| Race an Activity | Yes | Yes |
| Advanced workouts | Yes | Yes |
| Interval training | Yes | Yes |
| VO2 Max (trail run) | Yes | Yes |
| GPS speed and distance | Yes | Yes |
| Configurable lap alerts | Yes | Yes |
| Customizable data pages | Yes | Yes |
| Touch and/or button lock | Yes | Yes |
| Activity history on watch | Yes | Yes |
| Downloadable training plans | Yes | Yes |
| Training effect (anaerobic) | Yes | Yes |
| HRM running pace and distance | Yes | Yes |
| Heat and altitude acclimation | Yes | Yes |
| Customizable activity profiles | Yes | Yes |
| Auto Pause® automatic timer halt | Yes | Yes |
| Respiration rate (during exercise) | Yoga and Breathwork only | Yoga and Breathwork only |
| Auto Lap® interval tracking feature | Yes | Yes |
| Primary benefit (training effect labels) | Yes | Yes |
| Power modes (customizable in-activity battery settings) | Yes | Yes |
| HR broadcast (broadcasts HR data over ANT+® to paired devices) | Yes | Yes |
| Workout and Training Plans | ||
| Gym | Strength, HIIT, Cardio, Elliptical Training, Stair Stepping, Floor Climbing, Indoor Rowing | Strength, HIIT, Cardio, Elliptical Training, Stair Stepping, Floor Climbing, Indoor Rowing |
| Swim | Pool Swimming, Open Water Swimming | Pool Swimming, Open Water Swimming |
| Cycling | Biking, Road Biking, Mountain Biking, Gravel Biking, Bike Commuting, Bike Touring, eBiking, eMountain Biking, Indoor Biking, Cyclocross, BMX | Biking, Road Biking, Mountain Biking, Gravel Biking, Bike Commuting, Bike Touring, eBiking, eMountain Biking, Indoor Biking, Cyclocross, BMX |
| Wellness | Walking, Pilates, Yoga, Indoor Walking, Mobility | Walking, Pilates, Yoga, Indoor Walking, Mobility |
| Team sports | Basketball, Volleyball, Field Hockey, Ice Hockey, Football/Soccer, American Football, Lacrosse, Rugby, Ultimate Disc, Cricket, Softball, Baseball | Basketball, Volleyball, Field Hockey, Ice Hockey, Football/Soccer, American Football, Lacrosse, Rugby, Ultimate Disc, Cricket, Softball, Baseball |
| On the water | Stand Up Paddleboarding, Rowing, Kayaking, Fishing, Boating, Whitewater | Stand Up Paddleboarding, Rowing, Kayaking, Fishing, Boating, Whitewater |
| Racket sports | Tennis, Pickleball, Badminton, Squash, Table Tennis, Padel, Platform Tennis, Racquetball | Tennis, Pickleball, Badminton, Squash, Table Tennis, Padel, Platform Tennis, Racquetball |
| Indoor running | Treadmill Running, Indoor Track Running, Virtual Running | Treadmill Running, Indoor Track Running, Virtual Running |
| Outdoor running | Running, Outdoor Track Running, Trail Running | Running, Outdoor Track Running, Trail Running |
| Snow and winter | Skiing, Snowboarding, XC Classic Skiing, XC Skate Skiing, Ice Skating, Snowshoeing | Skiing, Snowboarding, XC Classic Skiing, XC Skate Skiing, Ice Skating, Snowshoeing |
| Outdoor recreation | Hiking, Climbing, Hunting, Horseback Riding, Archery | Hiking, Climbing, Hunting, Horseback Riding, Archery |
| Other activity profiles | Tactical | Tactical |
| Health & Wellness Monitoring | ||
| GPS | Yes | Yes |
| Compass | Yes | Yes |
| GLONASS | Yes | Yes |
| Galileo | Yes | Yes |
| Thermometer | Yes | Yes |
| Accelerometer | Yes | Yes |
| Barometric altimeter | Yes | Yes |
| Pulse Ox blood oxygen saturation monitor | Yes | Yes |
| Garmin Elevate™ wrist heart rate monitor | Yes | Yes |
| Safety and Tracking Features | ||
| XERO™ Locations | Yes | Yes |
| Dual grid coordinates | Yes | Yes |
| Kid Activity Tracking Features | ||
| Toe-to-Toe™ Challenges app | yes (optional Connect IQ Toe-to-Toe™ Challenges app) | yes (optional Connect IQ Toe-to-Toe™ Challenges app) |
| Training, Planning and Analysis Features | ||
| Run workouts | Yes | Yes |
| Race predictor | Yes | Yes |
| Foot pod capable | Yes | Yes |
| Running dynamics | Yes | Yes |
| Trail run auto climb | Yes | Yes |
| Run/walk/stand detection | Yes | Yes |
| Stride length (real time) | Yes | Yes |
| Vertical oscillation and ratio | Yes | Yes |
| Ground contact time and balance | yes (but not balance) | yes (but not balance) |
| GPS-based distance, time and pace | Yes | Yes |
| Cadence (provides real-time number of steps per minute) | Yes | Yes |
Wrist Fit
Garmin Instinct® E – 40 mm
Sits best on wrists ~42–57mm wide (≈ 11.2–15.2cm circumference).
Garmin Instinct® E – 45 mm
Sits best on wrists ~47–64mm wide (≈ 12.6–17.1cm circumference).
Frequently Asked Questions
Is the Garmin Instinct® E – 40 mm bigger than the Garmin Instinct® E – 45 mm?
The Garmin Instinct® E – 45 mm is bigger — 45mm vs 40mm case width.
Which fits a smaller wrist better, the Garmin Instinct® E – 40 mm or the Garmin Instinct® E – 45 mm?
The Garmin Instinct® E – 40 mm suits wrists around 42–57mm wide, and the Garmin Instinct® E – 45 mm around 47–64mm. The one with the smaller lower bound is the safer pick for a small wrist.
Can I see the Garmin Instinct® E – 40 mm and Garmin Instinct® E – 45 mm side by side at true scale?
Yes — the schematics and photos above show both watches at matched scale, and our fit tool overlays each on your wrist width.