20 tools available
⌘K
New · AI scan tool

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.

Try the toolFree · ~8s scan · ±4–5%
New · AI body transformation

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.

Transform my photoFree · ~20s · before/after slider
New · AI cut forecast

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.

Find my date rangeFree · ~30s · AI before/after
New · AI physique score

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.

Rate my physiqueFree · ~8s · 3 free ratings

Free Fitness Calculators

Twenty practical tools for body composition, progress, nutrition, and performance. Instant results, no signup.

Body Composition

13 tools

Body 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.

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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.

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Body Shape Compare

Compare current and goal measurements with two neutral 2D silhouettes. See which proportions differ without pretending to predict exactly how a body will look.

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Private Progress Photo Compare

Align two photos, switch between side-by-side, wipe, and ghost views, blur the face area, then export—all locally in your browser.

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Recomp Reality Checker

Read 4–12 weeks of weight, waist, strength, and optional body-fat signals together. Get a neutral pattern check with confidence and a next check-in date.

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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.

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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.

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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.

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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.

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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.

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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.

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Body Fat Calculator

U.S. Navy tape-measure method. Enter neck, waist, and hip circumferences to get your body fat percentage and category.

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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.

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Nutrition & Energy

3 tools

Performance & Output

3 tools

Documentation

1 tool

Frequently
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.

No. The comparison, alignment, optional privacy blur, and PNG export all run locally inside your browser tab. The image files are not uploaded.

No single calculator can prove muscle gain and fat loss. The recomp reality checker combines several 4–12 week signals, shows which ones agree or conflict, and tells you when more data would make the read clearer.

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.

Beyond the calculator

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.

iOS · iPhone
~60 sec to result
±2–4% vs DEXA
Free to start
Download on the App Store