Free Tools

Free fitness calculators

Eleven calculators for your training, nutrition, and recovery — no signup, no email required, no fluff. Same math we use inside the FitBear AI coach.

Nutrition & Body Composition

Total daily energy expenditure from BMR + activity. Your starting point for any cut, bulk, or maintain plan.

Protein, carbs, and fat targets tuned to your goal — cut, bulk, or maintain — with calorie totals.

U.S. Navy method using a tape measure. No calipers, no scales required.

Daily water target adjusted for bodyweight, training duration, and climate.

Estimate your 1RM from any working set with the Epley, Brzycki, and Lombardi formulas.

Convert your 1RM into estimated 3, 5, 8, and 10-rep maxes for programming.

Convert reps in reserve to percentage of 1RM, or estimate intensity from a working set.

Powerlifting strength scores normalized for bodyweight. Compare lifts across weight classes.

What plates do you stack on each side of the bar to hit your target weight? Includes visual.

Five training zones (Z1–Z5) from your max or resting heart rate. For runners, cyclists, and HIIT.

How long until that muscle group is ready for another hard session, based on volume and intensity.

FitBear runs all of these formulas on autopilot — calibrated to your Apple Watch recovery data and last week's training.

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