Body Fat Calculator
Free Body Fat Percentage Calculator
This body fat calculator estimates body fat percentage using body measurements. It is designed for general education and planning. Unlike BMI, body fat percentage attempts to estimate how much of your body weight may be fat mass compared with lean mass. However, tape-measure methods are still estimates and can vary based on how measurements are taken.
The calculator uses a simplified U.S. Navy-style measurement approach. Men use height, waist, and neck. Women use height, waist, neck, and hips. For best results, measure consistently, use the same tape, and avoid pulling the tape too tight.
Estimate body fat percentage
How to measure correctly
Measure your waist around the narrowest point or around the navel if that is easier to repeat. Measure your neck below the Adam's apple area while relaxed. For women, measure hips around the widest part of the buttocks. Stand normally, breathe out gently, and keep the tape level.
Why body fat percentage can help
Body fat percentage can provide more context than weight alone. Two people may weigh the same but have different body composition. Tracking waist measurements and body fat estimates over time can help you understand progress during fat loss or strength training.
Frequently Asked Questions
Is this body fat calculator accurate?
It is an estimate. Tape measurement methods can be helpful for tracking trends but are not as precise as clinical testing.
Should I use this instead of BMI?
Use both for context. BMI is quick, while body fat percentage gives more insight into body composition.
How often should I measure?
Every 2–4 weeks is usually enough. Daily measurement changes can be misleading.
Why does my result change if I measure slightly differently?
Small tape placement differences can change the result. Consistency is important.