"Is my FFMI good?" is the most-Googled question on the subject — and the most badly answered. Most calculators throw a single number at you and call it a classification. Reality is more nuanced: a good FFMI for a 25-year-old male who has lifted for 7 years is wildly different from the realistic target of a 19-year-old who just started. This guide gives you the actual benchmarks at every stage, height, and sex.

Quick Reference: What Counts as "Good"

For most readers searching this term, here is the headline answer for adult men:

  • FFMI 17–18: Untrained / general population average.
  • FFMI 19–20: A solid year of consistent training. "Athletic" appearance.
  • FFMI 21–22: Genuinely strong intermediate — 3–5 years of well-programmed lifting.
  • FFMI 23–24: Advanced natural lifter. 5–10+ years, optimized training and nutrition.
  • FFMI 25: The practical natural ceiling (Kouri et al., 1995).
  • FFMI 26+: Statistically rare without pharmacological assistance.

For women, subtract roughly 3 points from each band. A normalized FFMI of 18–19 is excellent natural development for a woman with several years of training.

FFMI by Training Age

Lyle McDonald's natural muscle-gain model (extrapolated from McRobert, Aragon, and Schoenfeld data) gives the most accurate expectations:

  • Year 1: +8–10 kg of lean mass. FFMI moves from ~17 to ~19.
  • Year 2: +4–5 kg. FFMI from ~19 to ~20.5.
  • Year 3: +2–3 kg. FFMI to ~21.5.
  • Year 4: +1–2 kg. FFMI to ~22.
  • Year 5+: 0.5–1 kg per year. FFMI to 23+ takes 7–10 years of optimized work.

This is why year-one gains feel magical and year-five gains feel like dragging a boulder uphill. The closer you are to your genetic ceiling, the slower every additional point comes.

FFMI by Height

Raw FFMI penalizes taller lifters because the height-squared denominator scales faster than absolute lean mass does. That is why normalized FFMI (FFMI + 6.1 × (1.8 − height in m)) exists — and why you should always compare normalized values.

Practical translation: a 195 cm lifter at "raw" FFMI 20 has nearly the same muscularity as a 170 cm lifter at FFMI 21.5. Don't compare yourself to shorter friends without correcting for height.

FFMI by Sex

Untrained female FFMI averages 14–15. Trained female athletes typically sit at 17–19, with elite naturals reaching 20–21. The ceiling is lower than for men due to roughly 10× lower testosterone, but the relative achievement at each band is identical.

If you are a woman benchmarking yourself, scale the men's table by −3 FFMI points and you will have a realistic target band.

FFMI by Age

Age does not move FFMI dramatically in healthy adults until the 50s, when sarcopenia begins. A few age-specific notes:

  • Under 18: Skeletal frame still developing. FFMI targets should be interpreted loosely.
  • 20s–30s: Prime muscle-building decade. The benchmarks above apply directly.
  • 40s: Add 1–2 years to the "training age" timeline above; recovery is slower.
  • 50+: Holding FFMI at year-2 levels (~20) is already a win. Focus shifts from "build" to "preserve".

Why Your FFMI Might Be Misleading You

Three measurement traps inflate or deflate FFMI:

  • Under-estimated body fat — using a smart scale that reads 12% when DEXA would say 18% inflates FFMI by ~1.5 points.
  • Heavy water retention — high-carb days, creatine loading, or pre-contest depletion can swing scale weight 2–3 kg and falsely move FFMI.
  • Forgetting normalization — comparing raw FFMI across heights produces apples-to-oranges results.

For the cleanest read: morning, fasted, post-bathroom weight + a body fat estimate from the US Navy method (cheaper and more consistent than smart scales).

So, What Is a "Good" FFMI for You?

Define "good" by trajectory, not by an absolute number. The right question is not "Is my FFMI good?" but:

  • Is my FFMI rising consistent with my training age?
  • Is my normalized FFMI above the untrained baseline (17 men / 14 women)?
  • Has it moved meaningfully in the past 6 months?

Plug your latest numbers into the FFMI Calculator every 8 weeks. The trend line tells you far more than any single classification band.

Bottom Line

"Good FFMI" is not a fixed target — it is a function of training years, height, age, and sex. For most adult men, normalized FFMI in the 21–23 range after 3–5 years of consistent lifting is excellent. For women, 18–20 in the same timeframe is the equivalent. The natural ceiling of 25 (men) / 22 (women) is reachable but takes a decade of disciplined work, not a single program.