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FFMI Calculator

Fat-free mass index — the muscularity measure that height-corrects where BMI cannot.

Related tools

All Strength training tools →
Army Body Fat CalculatorThe US Army AR 600-9 tape method, with the pass/fail limit for your age band.Bench Press CalculatorYour bench 1RM, the load for every rep range, and where it sits against your bodyweight.Body Recomposition CalculatorMaintenance calories, protein target and an honest feasibility score for losing fat while gaining muscle.Lean Body Mass to Strength CalculatorPredict your squat, bench and deadlift from lean mass, and score how much of that potential you've realised.Strength Standards CalculatorWhere your squat, bench, deadlift or press lands from untrained to elite for your bodyweight.Lift percentage of 1RM calculatorFind the weight to load for a given percentage of your one-rep max.One-rep max (1RM) calculatorEstimate your one-rep max from a weight lifted for several reps (Epley formula).Vertical jump calculatorYour vertical jump — the reach you gain leaving the ground — from your standing reach and jump reach, or entered directly. From the height it also derives your hang time and, with your body weight, an estimate of peak leg power (Sayers formula).

Open FFMI Calculator and you get an answer straight away, with no account to create. Its place is under Strength training; Army Body Fat Calculator and Bench Press Calculator answer the questions closest to this one.

How to use it

  1. Open the tool — no signup or install needed.
  2. Enter your input or adjust the available options.
  3. Get your result instantly, then copy or download it.

Frequently asked questions

What does FFMI Calculator do?

Fat-free mass index — the muscularity measure that height-corrects where BMI cannot.

When would I actually use this?

Programming a block: estimating a one-rep max without testing it, setting working loads as a percentage of it, and tracking whether volume is actually going up.

What is the most common mistake?

Estimating a one-rep max from a high-repetition set. The formulas hold to about five reps; beyond ten they drift badly, because endurance starts to dominate strength.

How is FFMI Calculator different from Army Body Fat Calculator?

They sit next to each other but answer different questions: Army Body Fat Calculator is the one to open when you need it to the US Army AR 600-9 tape method, with the pass/fail limit for your age band. Pick whichever matches what you're starting from — both are free.

Is there a tool for the next step?

Bench Press Calculator is the closest one after this: Your bench 1RM, the load for every rep range, and where it sits against your bodyweight.

What else is worth having open alongside it?

Body Recomposition Calculator and Lean Body Mass to Strength Calculator — they come up in the same task often enough to be worth a second tab.

Where do the figures come from?

The estimates use the published Epley and Brzycki equations, which the tool names. They were derived on trained lifters and describe a population, not your best day.

Further reading

All guides →
ExplainerFFMI: The Number BMI Cannot Give YouBMI weighs you and divides by your height squared. It cannot tell muscle from fat, which is why lean athletes get classed overweight. FFMI removes the fat first — and inherits every error in the body-fat estimate it is built on.GuideStrength Standards: What Counts as Strong, in Multiples of BodyweightA 176 lb man benching 220 lb is intermediate, not strong. Here are the usual bodyweight multiples for bench, squat and deadlift, and why the labels mislead more often than they help.ComparisonOne-Rep Max Formulas Disagree, and the Disagreement Is the PointEpley, Brzycki, Lombardi, O'Conner and Wathan are five curves through the same data. They agree within a few pounds at low reps and disagree by a quarter at fifteen — which is exactly how you know when an estimate is worth having.ExplainerClimbing Grade Conversions Are Not ConversionsFrench, YDS, UIAA, V-scale and Font are ordinal scales with no underlying unit. A conversion table is a negotiated alignment between climbing communities — and published tables disagree by half a grade at the top and by four letter-grades at the bottom of the boulder scales.How-toHow to Train With Percentages of Your 1RMPercentage-based training scales every lift to your one-rep max. Learn the strength and hypertrophy zones and how to set your working weights.ExplainerVertical Jump to Power: What the Conversion AssumesTurning jump height into take-off velocity is exact physics. Turning it into watts is a regression fitted on somebody else's athletes — and the three common formulas disagree by thousands of watts on the same jump.