计算您的无脂体重指数 (FFMI)
使用我们的专业FFMI计算器，获得准确的身体成分分析并追踪您的健身进度。适合运动员、健美运动员和健身爱好者。
调整后FFMI
经身高调整的FFMI，更准确地反映您的肌肉发展水平。这是主要参考值。
体脂率
使用Deurenberg公式（BMI + 年龄 + 性别）计算，并根据体型调整。
Deurenberg公式：体脂率 = (1.2×BMI + 0.23×年龄 - 5.4) - 10.8×性别
肌肉量
您的总瘦体重和身体成分分解
解读
基于您的调整后FFMI值的评估。
建议
基于您的FFMI值和体型特征的个性化建议。
训练重点
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营养建议
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目标设定
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计算器
年龄用于Deurenberg公式以准确计算体脂率
选择您的体型以估算体脂率
保存您的记录
将当前计算结果保存到历史记录，方便追踪您的进度
暂无历史记录
开始计算您的FFMI以追踪您的进度
What is FFMI (Fat-Free Mass Index)?
The Fat-Free Mass Index (FFMI) is a measurement that evaluates the amount of muscle mass you carry relative to your height. Unlike BMI, which treats all weight equally, FFMI specifically focuses on lean body mass—giving you a more accurate picture of your muscular development.
The FFMI Formula
Fat-Free Mass (FFM) = Weight × (1 - Body Fat %)
FFMI = FFM / Height²
Normalized FFMI = FFMI + 6.1 × (1.8 - Height)
The normalized FFMI adjusts for height differences, making comparisons between individuals more accurate. This correction was introduced by Kouri et al. (1995) in their landmark study.
Why FFMI is Better Than BMI for Athletes
BMI (Body Mass Index) has a fundamental flaw: it cannot distinguish between muscle and fat. A muscular athlete and an overweight sedentary person can have identical BMI scores, despite having completely different body compositions.
BMI Limitations
- • Cannot differentiate muscle from fat
- • Labels muscular people as "overweight"
- • Ignores body composition entirely
- • Not useful for fitness tracking
FFMI Advantages
- • Measures actual muscle mass
- • Accounts for body fat percentage
- • Height-normalized for fair comparison
- • Research-backed interpretation ranges
FFMI Score Interpretation
Understanding what your FFMI score means is crucial for setting realistic fitness goals. These ranges are based on research studies of both natural and enhanced athletes.
| FFMI Range | Category | Description |
|---|---|---|
| < 18 | Below Average | Little muscle development. Common in untrained individuals or those new to fitness. |
| 18 - 20 | Average | Typical for recreationally active men. Some visible muscle definition. |
| 20 - 22 | Above Average | Good muscular development. 1-3 years of consistent training typically required. |
| 22 - 23 | Excellent | Very muscular. Noticeably athletic build. 3-5+ years of dedicated training. |
| 23 - 25 | Superior | Elite natural development. Near genetic potential for most individuals. |
| > 25 | Exceptional | Exceeds typical natural limits. May indicate elite genetics or PED use. |
Important Note on the "Natural Limit"
The FFMI of 25 is often cited as the "natural limit," based on Kouri et al.'s 1995 study. However, this should be viewed as a general guideline, not an absolute rule. Genetics, measurement accuracy, and individual variation all play significant roles.
How to Use Your FFMI Score
Track Progress
Calculate your FFMI regularly (monthly or quarterly) to objectively track muscle gains. Unlike weight alone, FFMI shows if you are building lean mass.
Set Realistic Goals
Use FFMI ranges to set achievable targets. First-year gains are typically 2-3 FFMI points. Knowing your ceiling helps plan long-term.
Compare Fairly
FFMI normalizes for height, allowing fair comparison across different body sizes. A 5'6" and 6'2" lifter can be compared directly.
Assess Naturally
FFMI can help you evaluate whether physiques you see online are naturally achievable, helping set more realistic expectations.
什么是FFMI？
无脂体重指数（FFMI）是一种帮助您了解相对于身高的肌肉量的测量方法。与身体质量指数（BMI）不同，BMI无法区分脂肪和肌肉，而FFMI专门测量您的瘦肌肉量。
FFMI是1990年代研究合成代谢类固醇对肌肉量影响的研究人员开发的。Kouri等人在1995年进行的开创性研究发现，自然健美运动员的FFMI很少超过25，而类固醇使用者的数值通常高于这一阈值。
FFMI为何重要：
- 随时间追踪肌肉增长进度
- 设定现实的自然健美目标
- 公平地比较您与他人的体格
- 识别您是否达到遗传潜力
使用FFMI的好处
精准追踪
与BMI不同，FFMI专门测量肌肉量，为您提供更准确的身体成分和健身进度图像。
设定现实目标
了解您的自然增肌潜力，并基于科学研究和数据设定可实现的目标。
基于证据
基于领先运动科学机构的同行评审研究，为您提供可靠和值得信赖的结果。
常见问题
FFMI和标准化FFMI有什么区别？
常规FFMI是您的原始计算值，而标准化FFMI会调整身高以允许不同身高人群之间的公平比较。标准化公式将每个人的FFMI调整为假设身高为1.8米（约5英尺11英寸）时的数值。这是讨论自然极限时通常使用的值。
体脂率需要多精确？
体脂率的准确性对FFMI计算至关重要。体脂测量中5%的误差可能会使您的FFMI改变2-3个点。为获得最佳结果，请使用DEXA扫描或专业身体成分分析。目测估计或基本皮褶卡尺的误差可能达到5-10%，严重影响您的结果。
我可以自然地将肌肉增长到FFMI超过25吗？
可以，但很罕见。对大学运动员的最新研究显示，约有2.5%的人自然达到FFMI超过28。因素包括卓越的遗传、从年轻时开始的最佳训练、特定运动的适应性以及非凡的恢复能力。大多数自然健身者会在22-25 FFMI之间达到平台期。
作为自然健身者，我应该以什么FFMI为目标？
对于大多数专注的自然健身者来说，现实的目标是FFMI 21-23。这代表通过5-10年持续训练可实现的出色肌肉发展。FFMI超过23需要卓越的遗传以及多年近乎完美的训练和营养。
FFMI对女性的作用相同吗？
FFMI公式对女性的计算方式相同，但由于肌肉量潜力的生物学差异，参考范围不同。女性天然具有更高的体脂率和更低的肌肉量。女性FFMI 17-19被认为是优秀的，而19-21对于自然运动员来说是精英水平。自然情况下超过21的数值极为罕见。
More Questions About FFMI
What body fat percentage do I need to calculate FFMI?
You need to know your body fat percentage to calculate FFMI accurately. Common methods include: DEXA scans (most accurate), bioelectrical impedance scales, skinfold calipers, or visual estimation. If you don't know your body fat, use our Body Fat Calculator first, or try our FFMI estimator that works without it.
Is FFMI accurate for women?
The original FFMI research primarily studied men. For women, the scale is different: an FFMI of 15-17 is average, 17-19 is above average, and 19-21 is excellent. Women naturally carry less muscle mass, so direct comparison to male ranges is not appropriate.
Can FFMI detect steroid use?
FFMI alone cannot definitively detect steroid use. While scores above 25 are rare naturally, some individuals with exceptional genetics may exceed this. Conversely, many steroid users have FFMIs below 25. Use FFMI as one data point, not a definitive test.
How often should I measure my FFMI?
Muscle building is slow—measuring monthly or quarterly is sufficient. More frequent measurements may show fluctuations due to water retention, food intake, and measurement error rather than actual muscle changes. Track trends over months, not weeks.
Does FFMI account for bone density or frame size?
No, FFMI does not directly account for bone density or skeletal frame size. Individuals with larger frames may have slightly higher FFMIs. Some researchers have proposed adjusted formulas, but the standard FFMI remains the most widely used and researched version.
科学研究
Kouri等人（1995）
建立基线值的原始FFMI研究：
- 类固醇使用者：平均24.8 FFMI
- 自然健身者：平均21.8 FFMI
- 没有自然健身者超过FFMI 25
NCAA研究（2017）
关于大学运动员的研究：
- 26.4%的人FFMI超过25
- 挑战严格的自然极限
- 注意到特定运动的差异
最新研究（2019-2023）
现代研究发现：
- 特定运动的FFMI差异
- 遗传和训练因素
- 自然极限超过25
Scientific References
Kouri EM, Pope HG Jr, Katz DL, Oliva P. (1995)
"Fat-free mass index in users and nonusers of anabolic-androgenic steroids."
Clinical Journal of Sport Medicine, 5(4):223-228.
Schutz Y, Kyle UU, Pichard C. (2002)
"Fat-free mass index and fat mass index percentiles in Caucasians aged 18-98 y."
International Journal of Obesity, 26(7):953-960.
VanItallie TB, Yang MU, Heymsfield SB, et al. (1990)
"Height-normalized indices of the body's fat-free mass and fat mass."
American Journal of Clinical Nutrition, 52(6):953-959.
Medical Disclaimer
This calculator provides estimates for educational and informational purposes only. It is not medical advice and should not be used as a substitute for professional medical guidance. The FFMI metric has limitations and may not accurately represent all individuals. Consult a healthcare professional or certified fitness trainer before making decisions based on these calculations.