Strava vs Garmin Calorie Burn Calculator - Kilojoules & Firstbeat HR
Why does Garmin show 850 kcal while Strava shows 650 kcal? Discover the science of human mechanical efficiency and calculate exact metabolic burn.
How to Use Calorie Burn Science in 3 Simple Steps
Step 1: Upload
Drag & drop your .FIT, .GPX, or .TCX activity file. All processing is 100% private in your browser.
Step 2: Process
FitCrop inspects telemetry streams, removes anomalies, recalibrates metrics, or fixes binary checksums.
Step 3: Export
Download your clean Strava, Garmin, and Zwift compatible file with 1 click. Zero server wait.
Frequently Asked Questions
Why do Garmin and Strava show different calorie counts?
Garmin separates active exercise calories from resting basal metabolic calories using Firstbeat HRV algorithms. Strava calculates gross calories, which includes basal burn during the workout time.
Why does 1 kilojoule on a cycling power meter equal 1 food calorie (kcal)?
Because human muscular efficiency on a bicycle is approximately 20-25% (mean ~24.1%). The 4.184 factor converting kJ to kcal is almost perfectly cancelled out by the human body efficiency factor.