Free tools

Fitness calculators

Open calculators for calories, macros, protein, and strength estimates. Use them free, then log your targets in Refyuel Health OS.

Nutrition

TDEE calculator
Free TDEE calculator using the Mifflin-St Jeor equation. Estimate maintenance calories, fat loss, and muscle gain targets. For education only.
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Macro calculator
Free macro calculator: enter daily calories and protein target to split carbs and fat. For gym-goers tracking nutrition. Educational only.
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Protein calculator
Calculate daily protein in grams from body weight and g per kg. Common ranges for fat loss, maintenance, and muscle gain. Educational only.
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1RM calculator
Estimate your one-rep max (1RM) from weight and reps using the Epley formula. Same approach as Refyuel Health OS strength tracking. Educational only.
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Educational only - not medical advice. Health disclaimer

On the web: answer a few questions and create your account. Workouts and nutrition live in the Health OS app on Android or iOS.