Body fat from one photo.
AI reads the visual cues from a single gym selfie and returns a body fat percentage with confidence. No tape, no calipers, no signup — one free estimate per day.
See your after photo, a year early.
Upload one photo and AI renders the transformation a year of training builds — same face, same setting, your body. Slide from realistic to fantasy, pick the areas to grow.
Put a date range on your six pack.
Upload a current photo, choose your calorie deficit, and get a realistic visible-abs window—plus an AI preview of the leaner you. One flow from starting point to finish line.
Rate my physique, honestly.
Upload one photo and get a 1–100 physique score, broken into body fat, muscle, proportions, and goal fit — plus the one change that would move it most. No signup.
Free Fitness Calculators
Seventeen evidence-based tools for body composition, nutrition, and performance. Instant results, no signup.
Body Composition
10 toolsBody Visualizer
Enter height and weight to calculate adult BMI and see an illustrative male or female body-shape reference. Metric or U.S. units, no signup.
Open →Body Measurements & Proportions
Map chest, waist, shoulders, arms, thighs, wrist and height. Compare five ratios, set target sliders, then preview the regional changes on your photo.
Open →Body Fat % at Each Age
Drag two sliders to explore body fat percentages at every age — male and female, 20s through 60s. A photorealistic visual reference atlas, no guesswork.
Open →AI Body Fat from Photo
Upload one photo, get an AI body fat estimate in seconds. No tape, no calipers. One free estimate per day.
Open →AI Body Transformation
See yourself after a year of consistent training — AI renders your future body on your own photo. One free render, before/after slider.
Open →AI Physique Rater
Upload one photo, get a 1–100 physique score with body fat, muscle, proportions, and goal-fit sub-scores. Three free ratings.
Open →Six Pack Timeline
Upload a photo, choose a calorie deficit, and get your estimated weeks to defined abs — plus an AI preview of the leaner you.
Open →AI Ab Analyzer
Scan your abs from one photo: a 1-100 six pack score, upper and lower ab reads, and a months-to-visible-abs estimate. Three free scans.
Open →Body Fat Calculator
U.S. Navy tape-measure method. Enter neck, waist, and hip circumferences to get your body fat percentage and category.
Open →FFMI Calculator
Fat-Free Mass Index — how close your lean mass sits to the natural ceiling (~25). Weight, height, body fat in; physique tier out.
Open →Nutrition & Energy
3 toolsTDEE Calculator
Total daily energy expenditure — the calorie foundation of any diet. Mifflin-St Jeor formula with activity multiplier.
Open →Macro Calculator
Protein, carb, and fat targets calibrated to your TDEE and goal — cut, maintain, or bulk. Grams per day and per meal.
Open →Calorie Deficit Calculator
Daily calorie target, projected timeline, and milestone dates. Works for cuts and lean bulks alike.
Open →Performance & Output
3 tools1RM Calculator
One-rep max from six classical formulas, plus training percentages for every rep range. Untrained to Elite tier.
Open →Strength Standards
Eight compound lifts benchmarked Untrained → Elite. Get your percentile rank and the weight that unlocks the next tier.
Open →Calories Burned
Search 240+ activities. Enter weight and duration; get calories burned with food-equivalent comparisons.
Open →Documentation
1 toolFrequently
asked
questions
Common questions about the math, the methods, and what lies beyond the calculator.
Yes — every calculator is 100% free. No account, no email, no signup. Enter your measurements, get your result instantly. The GainFrame iOS app extends this with AI-powered photo analysis and ongoing tracking.
The U.S. Navy tape-measure method has been validated to within ±3–4% of DEXA for most people — one of the most reliable self-assessment tools available. GainFrame's AI photo analysis can provide a more precise estimate from a single image.
TDEE — Total Daily Energy Expenditure — is the total calories you burn per day, rest plus activity. It's the foundation of every diet: eat under it to lose fat, at it to maintain, above it to build muscle.
Set the goal to lean bulk — roughly 300 calories above TDEE. The calculator prioritizes protein (~0.8g per lb of bodyweight), caps fat at ~25% of calories, and fills the remainder with carbs. Pair with progressive resistance training.
Yes. GainFrame is an iOS app that analyzes your progress photos with AI and returns body fat %, FFMI, twelve muscle scores, and macro recommendations — from a single photo, in under a minute.
One photo.
A complete body
composition report.
GainFrame’s AI analyzes your progress photos and returns body fat %, FFMI, twelve muscle scores, and custom macros — in under 60 seconds.
~60 sec to result
±2–4% vs DEXA
Free to start
