Body Fat Percentage Calculator – Measure Your Fitness

The Body Fat Percentage Calculator gives you a clearer picture of your body composition than weight or BMI alone ever could. Two people can have the exact same BMI and look completely different in terms of fitness — because BMI does not distinguish between muscle and fat. Body fat percentage does. It tells you what proportion of your total body weight is made up of fat tissue, which is a far more meaningful measure when you are trying to understand your fitness level, track changes over time, or set realistic health goals. Enter your height, weight, age, and gender, and the calculator uses the Boer formula to estimate your body fat percentage and place it within the recognized fitness categories — from Essential Fat and Athlete all the way through to Obese — so you always have proper context for the number you receive.

Formula Used (Boer Formula): Males: BFP = (1.20 × BMI) + (0.23 × Age) − 16.2 Females: BFP = (1.20 × BMI) + (0.23 × Age) − 5.4

How to Use the Body Fat Percentage Calculator

The process is quick and requires only four pieces of information:

Select Your Unit System by choosing either Metric (cm and kg) or Imperial (inches and lbs) from the dropdown. The input fields update automatically to match your selection, and decimal values are accepted for more precise measurements.

Enter Your Height in centimetres or inches depending on your chosen unit system. A value like 170 cm or 67 inches works fine, and you can include a decimal if you want greater accuracy.

Enter Your Weight in kilograms or pounds. As with height, decimal values are fully supported — so 72.5 kg or 160.3 lbs is just as valid as a rounded figure.

Enter Your Age as a whole number. Age is a meaningful factor in body fat estimation because fat distribution and body composition shift naturally as we get older, and including it makes the result more accurate and relevant to your actual situation.

Select Your Gender by choosing Male or Female. Body fat percentage categories differ significantly between men and women — what is considered athletic or healthy varies by gender — so this input ensures the classification you receive is the right one for you.

Click Calculate and your body fat percentage appears immediately alongside your fitness category and a complete reference table showing all body fat percentage ranges for your gender, so you can see exactly where your result sits within the full spectrum.

Why Use the Body Fat Percentage Calculator Online?

A More Meaningful Measure Than BMI Alone: BMI is useful as a broad screening tool, but it treats all body weight the same regardless of whether it comes from muscle or fat. Body fat percentage separates the two, making it a significantly more informative metric for anyone who exercises regularly, is building muscle, or wants to understand their body composition rather than just their weight relative to height.

Gender-Specific Categories for Accurate Classification: The body fat ranges that define Essential Fat, Athlete, Fitness, Average, and Obese differ between men and women. The calculator applies the correct set of categories based on the gender you select, so the classification you receive is meaningful and not based on a generic unisex scale that would misrepresent results for a large portion of users.

Full Reference Table Always Visible After Calculation: Rather than showing only your individual result, the calculator also displays the complete body fat percentage range table for your gender every time you calculate. This gives you the context to understand not just where you are, but how far you are from adjacent categories in either direction.

Supports Both Unit Systems Without Manual Conversion: Metric and imperial inputs are both handled natively. Switching between them adjusts the fields automatically, so there is no need to convert your measurements beforehand regardless of which system you are most comfortable working in.

Free, Private, and Instantly Accessible: No registration, no data storage, and no cost. Open the calculator, enter your four measurements, and get a clear body fat percentage estimate with full category context in seconds.