Free tools
Fitness calculators & guides
Five free calculators and practical physique guides — understand the numbers and make more useful comparisons.
FFMI Calculator
Fat-Free Mass Index — estimated fat-free mass relative to height, not a direct muscle measurement.
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BMI Calculator
The standard number, plus an honest take on where it breaks down.
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One Rep Max Calculator
Estimate your 1RM from any weight and rep count, plus a % table.
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Lean Body Mass Calculator
With a body fat % you know, or estimated without one.
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Macro Calculator
Daily calorie, protein, carb and fat targets for your goal.
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Numbers are half the picture
Every calculator here gives you a number based on a formula — useful, but formulas don't know what you actually look like. If you want the other half, CutRank gives an AI visual estimate from one photo: an S–E grade, scores for visible muscle groups, and a suggested focus. Photo conditions affect results.
Get your grade — free
One photo, graded S to E. No card.
Physique guides
Understand the numbers, improve your comparisons, and explore the questions behind your physique goals.
Why are my lower abs not showing?
Upper abs visible but lower abs not showing? Understand regional definition, check your photos fairly, and separate useful training from spot-reduction claims.
Why are my abs only visible when flexing?
Abs show when flexing but disappear at rest? Learn what the difference means, how to compare progress photos, and why it cannot identify your body fat.
Why do my abs look uneven?
Understand why abs can look uneven or staggered, what training can change, and how to compare photos without treating normal variation as a diagnosis.
FFMI vs BMI: the difference is what you count
Compare FFMI and BMI with a worked example. Understand total weight versus fat-free mass, why results differ, and which number fits your tracking question.
Normalized FFMI: what the height correction changes
Learn how normalized FFMI differs from raw FFMI, calculate a worked example, and understand CutRank's 6.1 convention versus the original study's 6.3.
Lean body mass is not the same as muscle mass
Understand lean body mass, fat-free mass and skeletal muscle. See a worked calculation, decode DXA lean tissue, and compare progress with clearer labels.
Am I losing muscle while cutting?
A lighter scale or flatter muscles do not prove muscle loss. Learn which trends to compare during a cut, and what body-composition readings can miss.
How accurate is your body-fat measurement?
Compare smart scales, skinfolds, DXA and photo estimates. Understand why methods disagree and how to track body fat without trusting false precision.
How to take physique progress photos you can compare
A repeatable setup for front, back and side progress photos: camera height, distance, lighting and pose, plus a checklist for comparing physique changes.
What is a V-taper physique?
Understand the V-taper silhouette, the roles of shoulders and lats, and how to assess progress without chasing a universal shoulder-to-waist ratio.
One pec bigger than the other?
Fair photo checks, unilateral chest training and when to seek individual assessment.