RFM (Relative Fat Mass) Calculator

How do you Calculate Relative Fat Mass?

Calculating relative fat mass requires the following variables:

• Sex


• Height


• Waist measurement

• RFM = Relative fat mass


• SC = Sex constant (if male this is 64, if female this is 76)


• H = Height


• W = Waist

Understanding Your Results

Your result from this calculator will be a percentage. That is the relative fat mass of the body that you defined with your entries. If the result you get is 20% that would mean that about 20% of your body is made up of fat. The higher the number, the higher the fat content of your body potentially. There are some limitations with this calculator. Some of these include genetics, muscle mass, age, and ethnicity.

How to Use the Relative Fat Mass Tool

Our relative fat mass tool is designed to be easy and efficient to use. The steps involved with using this tool includes:

1. Choose the sex.


2. Enter the height in feet. If you are 5 feet 11 inches tall, you would enter 5 here.


3. Enter the height in inches. If you are 5 feet 11 inches tall, you would enter 11 here.


4. Enter the circumference of your waist.


5. Hit the calculate button and instantly get your relative fat mass result!

Calculation Example

Let's say someone wants to find out what their relative fat mass is. They can use this tool to do so. They are a male who is 6 feet tall, with a waist of 35 inches. To use this tool they would enter 6 into the height - feet field. Then they would enter 0 into the height - inches field. The last thing needed is their waist measurement, so they would enter 35 into that field.

We can now hit calculate and get our answer. Once we do we learn that the relative fat mass of a person with those specs is 22.86%.