Calculator

Body Fat Calculator

Estimate your body fat percentage from height, weight, age and sex.

Built by Menang7, owner of LeanMassCalculator.com

Lean Mass vs Muscle Mass →
Method
Units

Measure your neck just below the larynx and your waist at the navel (women: the narrowest point). Women also measure hips at the widest point. Keep the tape snug but not tight.

Guide

Lean Body Mass vs Muscle Mass

Body fat is only half the picture. Learn how lean mass differs from muscle mass and which one to track.

Read the guide →

How body fat is estimated

Direct measurement needs a DXA scan, underwater weighing or skinfold calipers. This calculator uses a population formula built on body mass index (BMI), age and sex: body fat % = 1.2 × BMI + 0.23 × age − 10.8 × sex − 5.4 (sex = 1 for men, 0 for women).

It works well for the average person but can over-estimate body fat in muscular people and under-estimate it in people who have lost muscle. If you want a measurement that reflects where you carry fat, switch to the tape-measure method, which uses the US Navy formula with your neck, waist and, for women, hips.

Body fat percentage ranges

CategoryWomenMen
Essential fat10–13%2–5%
Athletes14–20%6–13%
Fitness21–24%14–17%
Average25–31%18–24%
Above average32%+25%+

Ways to measure body fat

DXA scanThe most practical accurate method. Also splits fat, lean and bone mass by body region.
Skinfold calipersCheap and repeatable when done by the same trained person each time.
Smart scalesConvenient for trends, but readings change with hydration.
Tape measureWaist, neck and hip measurements feed the US Navy formula, a good home option.

Frequently asked questions

What is a healthy body fat percentage?
For most adults, about 14–24% for men and 21–31% for women falls in the fitness to average range.
Is BMI-based body fat accurate?
It is an estimate with a margin of several percent. Use it to track trends rather than as a precise value.
Can I have too little body fat?
Yes. Below essential levels, hormones, immunity and bone health suffer.
How fast can I lower body fat?
A loss of 0.5–1% of bodyweight per week is a sustainable pace that helps preserve muscle.
Which method should I use, BMI or tape measure?
The tape-measure (US Navy) method uses your neck, waist and hips, so it reflects where you carry fat. The BMI method is quicker. Try both and track whichever you can repeat consistently.
Is lean mass the same as muscle mass? Read more →

Related

🥩Protein Intake CalculatorFind a daily protein target based on your lean mass and goal.Open →💪Muscle Mass CalculatorRough estimate of skeletal muscle mass from your lean body mass.Open →📏Lean Mass Index (LMI)Lean mass divided by height squared: a fairer way to compare builds.Open →🧮Lean Mass CalculatorEstimate your lean body mass from height, weight, age and sex.Open →📝Healthy Lean Mass Percentage by AgeWhat is normal at 20, 40 and 60, and what to aim for.Open →🧰All ToolsEvery calculator in one place.Open →

About Menang7, the developer

This calculator is part of LeanMassCalculator.com, developed, owned and maintained by Menang7. For questions about how it works or your results, Menang7 is the person to look for.

For personal medical or nutrition decisions, please also speak with a doctor or registered dietitian.