Fat-Free Mass Index is a lesser-known but more precise alternative to the Body Mass Index (BMI). BMI measures a person’s body mass in relation to his/her height to determine if a person is healthy or obese. BMI is flawed because being heavy doesn’t really mean being obese. Bodybuilders are very heavy and have a high BMI but they are strong, healthy, and active individuals. That's where FFMI comes in. It measures a person’s muscle mass (i.e. fat-free mass) in relation to a person’s height and weight. It is formulated to distinguish between the weight of the fat and the weight of the muscles. Higher FFMI means more muscle mass and lower FFMI means more fat mass. Use our FFMI calculator to find out where you stand. Keep reading to find out more about the FFMI formula, why it is better than BMI, for whom it is relevant, and why you should care about your FFMI.
💡 Quick Tip: Want to workout from the comfort of your home? Need an all-in-one compact exercise machine that can help you target all major muscle groups of your body? I recommend Total Gym XLS. It is meant for beginners as well as intermediate-level fitness enthusiasts and can be used by people of all age groups.
Total Gym XLS
Out Fat-Free Max Index (FFMI) Calculator
FFMI Calculator
What is FFMI?
As I said above, the Fat-Free Mass Index i.e. FFMI is very similar to BMI but it is more trustworthy for measuring a person’s overall health. It measures the amount of muscle mass a person has, which doesn’t include fat.
Wondering what fat-free muscles are? They are your organs, bones, water, blood, nerves, connective tissues, and muscles.
FFMI indicates how much lean muscles you have. It can also help you predict how much muscle you need to gain to fall into the healthy category and how much fat you need to lose for that. Although it is relevant for all of us, the Fat-Free Mass Index is most relevant for bodybuilders and athletes. It is often used as a measure to determine their exercise goals and, sometimes, it also helps evaluators decide if the muscles are built naturally or with the help of steroids.
Wondering how? See the chart below.
📖 Related Article: If you are an aspiring bodybuilder, you might be interested in our article that explains if it is possible to gain muscles without eating a lot.
FFMI reference chart
There are separate charts for men and women. That's because women need to have more essential fat in their bodies so they can carry on with menstruation and reproduction without suffering from deficiencies.
FFMI Range for men
| FFMI range | Body fat percentage | Health status |
| 17-18 | 10-18% | Skinny |
| 18-20 | 20-27% | Average |
| 19-21 | 25-40% | Fat |
| 20-21 | 10-18% | An active healthy person |
| 22-23 | 6-12% | Advanced trainer |
| 24-25 | 8-20% | Bodybuilders |
Various studies have concluded that achieving 25+ FFMI may indicate the use of steroids for muscle enhancement because it is very very difficult to have such a high muscle mass naturally.
If you want to gain more muscles without using steroids, you can use creatine supplements such as BULKSUPPLEMENTS.COM Creatine Monohydrate Powder. High-quality 100% whey protein isolates such as Dymatize ISO 100 Whey Protein Powder are also great for people who want to build more lean muscles naturally.
FFMI range for women
| FFMI range | Body fat percentage | Health status |
| 14-15 | 20-25% | Skinny |
| 14-17 | 22-35% | Average women |
| 15-18 | 30-45% | Fat/obese |
| 16-17 | 18-25% | Active women |
| 18-20 | 15-22% | Athlete |
| 19-22 | 15-30% | Advanced trainer or bodybuilder |
💡 Quick Tip: Did you know spinning is one of the most effective exercises for building lean muscle and achieving an ideal FFMI? It is especially recommended for people with knee problems who can’t do other forms of cardio workouts. If you are looking for an affordable but compact spin bike that you can use in your bedroom or living room without disturbing others, I recommend the Eulumap stationary indoor exercise bike.
Eulumap stationary indoor exercise bike
How to calculate your Fat-Free Mass Index?
We have already created a calculator that you can use to find out what your FFMI is.
We have used the exact FFMI formula that is listed in the National Library of Medicine (2). It is (fat-free body mass in kg) x (height in meters)-2.
Fat-Free body mass can be calculated using the formula-
FFM= weight [kg] * (1 – (body fat [%]/ 100))
You can calculate your body fat for the above formula using our Navy method body fat calculator, YMCA body fat calculator, or Covert Bailey body fat calculator.
Why should you worry about FFMI?
As I have already said above, FFMI fixes the loopholes left by BMI. The better your FFMI score is, the healthier you are supposed to be. Lower FFMI makes you prone to obesity, heart disease, high blood pressure, type 2 diabetes, gallstones, sleep apnea, and even cancer. Use our FFMI calculator today to determine the state of your health. If it is poor, act immediately. Start eating healthy, home-cooked, nutritious meals. Plus, make sure you exercise at least for one hour every day. Our website has numerous workout guides that can help you get started in whichever way you want.
FFMI may not be 100% accurate but it is probably the most accurate means of judging a person’s overall health because after all it is all about having the right muscle mass and the right amount of fat in your body.
💡 Quick Tip: Looking for keto-friendly protein powders? Isopure Whey Isolate Protein Powder is one of the top-rated products you may try. It has zero carbs. Plus, it is rich in vitamin C and zinc that helps boost immunity.
Isopure Whey Isolate Protein Powder
Wrap up
Fat-Free mass index is slowly gaining popularity among fitness enthusiasts who have realized that BMI has been confusing and misleading them for decades. I hope this article has helped you understand its concept and importance. If you have questions, please email me or leave a comment. Keep reading our other articles to learn about tips and tricks to stay fit and eat healthy.
References and Citations
1- Clinical Journal of Sports Medicine- Fat-Free body mass index
2- National Library of Medicine- Fat-free mass index in users and nonusers of anabolic-androgenic steroids
