Free fitness calculators

Estimate total daily energy expenditure from Mifflin-St Jeor, Harris-Benedict, or lean-mass formulas. Free, no signup.

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Basal metabolic rate — calories at rest — using Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle.

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Protein, carb, and fat targets from your TDEE and goal — cut, maintain, or lean bulk. Grams per day.

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Daily calorie target, projected timeline, and a realistic weekly rate. Works for cuts and slower fat loss.

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How many calories to eat to hold your current weight — TDEE framed as a maintenance target.

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Calorie and protein targets for a fat-loss phase, plus an estimated weekly rate that protects training.

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A small surplus, protein target, and expected gain rate for a lean bulk — not a dirty bulk.

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Daily protein in grams from body weight and goal — cut, maintain, or lean bulk — plus a per-meal split.

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Pick a weekly rate and goal weight. Get a calorie target and a date range — not a fake exact day.

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Should you cut, lean bulk, recomp, or maintain? A short quiz from body fat, training age, and goal — not a vibe check.

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Daily water target from body weight and activity, in liters, ounces, or cups. Hammr scales the same way in the app.

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U.S. Navy tape-measure method. Neck, waist, and hip circumferences in, body-fat percentage and category out.

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Fat-Free Mass Index from weight, height, and body fat — how muscular you are relative to your frame.

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Fat-free mass and fat mass from scale weight and body-fat percentage, in lb or kg.

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Map chest, waist, shoulders, arms, thighs, wrist, and height. See five ratios against common aesthetic landmarks.

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Align two photos, wipe or sit them side-by-side, optionally blur the top of the frame, and export. Nothing uploads.

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Read 4–12 weeks of weight, waist, strength, and optional body fat together. A neutral pattern check — not a proof.

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Estimate 1RM from a working set using Epley and Brzycki, then see training percentages for every rep range.

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Turn a set with RPE into an estimated one-rep max. Reps in reserve become extra reps in the 1RM formula.

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Plates per side for a target weight on a 45 lb or 20 kg bar. Visual loadout for lb and kg gyms.

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Bench, squat, deadlift, press, and row from Untrained to Elite by body weight. See the load that unlocks the next tier.

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Weekly hard sets per muscle group versus MEV / MAV / MRV landmarks. See what is too little, productive, or likely junk.

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3–6 days: full body, upper/lower, or PPL. A week you can actually run — then open it in Hammr.

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Search 30+ activities. Enter weight and duration; get session calories plus a net and compensation-aware estimate.

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Calories burned walking from body weight, pace, and duration or distance. Includes net extra vs sitting.

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Calories burned running from pace and body weight, with net extra vs rest. Built for the same outdoor modes Hammr tracks.

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Karvonen zones from age and resting heart rate, plus Fox and Tanaka max-HR estimates. Five training zones.

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Upload a meal photo. AI estimates calories and macros. Two free scans per day — then log every meal in Hammr.

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Describe a meal in plain language. Get a calorie and macro estimate. Three free reads per day.

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One gym photo in, a body-fat range and confidence out. One free estimate per day. Wellness estimate, not DEXA.

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See a six-month projection from your current weight, body fat, and calorie target — cut, recomp, or lean bulk.

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Put a date range on visible abs. Current body fat plus a deficit, then weeks to a defined-abs window.

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