Why Does My Heart Rate Look Different in Other Apps?

It’s completely normal to see slight differences in heart rate values between Cardiogram and other apps like Apple Health, Fitbit, Garmin Connect, or Google Fit.

These differences usually come down to how each app processes and displays your heart data.

🧠 How Cardiogram handles heart rate data

Cardiogram pulls heart rate data from your wearable (Apple Watch, Fitbit, Garmin, or Wear OS), but it may be displayed differently than in the manufacturer’s app due to how we format the Timeline.

Here’s how it works:

On your Timeline, Cardiogram displays your heart rate in one-minute intervals
We either:
- Average all heart rate readings recorded during each one-minute segment, or
- Show the highest reading recorded in that minute
During continuous mode or workouts, your device may capture heart rate data every few seconds — these are then averaged into one data point per minute

📊 This creates a cleaner, more digestible chart, but may smooth out short spikes or drops.

🔺 Why the Peak BPM at the top may be higher than what you see on the chart

You may notice that the peak heart rate value listed at the top of your Timeline is higher than any value shown directly on the graph.

This is because:

The Timeline graph displays one-minute averaged values
The Peak BPM reflects the absolute highest individual heart rate reading recorded that day — even if it only occurred for a moment

So, even if that spike doesn’t appear on the graph (due to averaging), we still surface it to give you a more complete picture of your heart activity.

📉 Why other apps may show different values

Each platform handles heart rate visualization differently:

⌚ Apple Health

Shows detailed second-by-second data
May highlight each peak individually, even if brief

📱 Fitbit App

Shows a summarized daily graph
Brief spikes (like a high reading during a workout) may be left out unless they were sustained
You can usually see peak values by tapping into the specific workout view

🛰 Garmin Connect

Averages heart rate data in two-minute intervals
Short-term spikes may not appear in daily summaries
For detailed readings, you may need to explore the workout-level view

Learn more here: Why Do I See Two Different High Heart Rate Values in Garmin Connect?

📌 What this means for you

If you see a 171 BPM peak in Cardiogram but not in Fitbit or Garmin:

That spike likely did happen, but was only sustained briefly
Cardiogram may display it depending on how the data came in
Fitbit or Garmin may leave it out in favor of average or smoothed data

💬 Still have questions?

We’re happy to help review any data differences. Email us at [email protected] with:

A screenshot of the measurement in Cardiogram
A screenshot from the other app for comparison