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Free tools
Free tools for
Garmin runners
Quick, no-signup calculators to plan smarter training. Built by the team behind Custom Gains — the AI coach that turns your Garmin into a plan.
Heart rate zone calculator
Your 5 training zones in BPM — the same zones Garmin uses. Includes the Karvonen method.
Open tool →Race time predictor
One recent race in, your predicted 5K, 10K, half and marathon times and paces out.
Open tool →Overtraining check
Enter your morning recovery signals and find out if today should be hard, easy, or rest.
Open tool →Want all of this, automatically?
Custom Gains reads your Garmin, builds your weekly plan in the right zones, predicts your race, watches your recovery, and pushes every workout to your watch — without you running a single calculator.
Build my Garmin plan — free30 days free · code FOUNDING · cancel anytime
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