How to use it
Fill in the fields - the answer updates as you type. Estimate your body fat percentage from height, neck, waist (and hips for women) with the US Navy method - just a measuring tape.
Free and private
The calculation runs in your browser. Nothing you type is sent or stored, and there is no limit.
Questions
How accurate is it?
Usually within 3-4% of a lab DEXA scan when measured carefully.
Is it free?
Yes - free and unlimited, with no sign-up.