How Does Your Garmin Know You've Climbed a Floor?
It's not GPS. It's a barometric altimeter — your Garmin measures tiny changes in air pressure as you go up stairs. Here's exactly how it works.
Day 9: The Barometric Altimeter
"How does your Garmin watch know how many floors you've climbed?"
This one surprises a lot of people. GPS can tell you your altitude, but it's not accurate enough (or fast enough) to detect a single floor. Garmin uses a completely different approach.
The barometric altimeter
Air pressure decreases as you go higher. This happens on a large scale (mountains vs sea level) but also on a very small scale — climbing one flight of stairs changes the air pressure around you by a measurable amount.
Garmin watches with a barometric altimeter contain a tiny pressure sensor. When you climb roughly 10 feet (3 metres) in elevation, the watch registers one floor.
Why it sometimes gets it wrong
- Elevators: Fast pressure change = floors counted, even though you didn't climb
- Weather changes: Atmospheric pressure changes with weather. The watch recalibrates regularly but can drift
- Riding in a car: Going up a hill counts floors even without stairs
How to check if your Garmin has a barometric sensor
Not all Garmin models include a barometric altimeter. Check your model's spec page on garmin.com. Entry-level models (Forerunner 55, Vivoactive) often use GPS altitude instead — which is far less accurate for floor counting.
If accurate floor counting matters to you (you climb a lot of stairs at work), make sure your Garmin has a barometric altimeter before buying.
Join the Garmin School
Leave your email to get access to the Garmin School and receive updates on new videos and apps.
What to read next
Day 871Find the Right Garmin Watch With the Compare Tool
Garmin's catalogue is crowded. Describe your activities, required features, and budget to get a focused shortlist, then compare the watches side by side.
Day 861How to Import a GPX File Into Garmin Connect
Start with 10 useful websites for free and paid GPX routes, then import the file into Garmin Connect and send the course to a compatible watch or Edge.
