Tools

Body Composition Calculator

Two measurements, one honest number. This returns your waist-to-height ratio, an estimate of your body fat, and the size of the gap between where you are and the top of the healthy range.

The formula uses a different constant for each. It is the only place this input is used.

Measure at the belly button, standing, at the end of a normal breath out. Not where your trousers sit.

Takes about 40 seconds

How this is worked out

Every formula below is published, and so is where it comes from. If you disagree with one, you can check it rather than take our word for it.

Waist-to-height ratio
ratio = waist ÷ height NICE recommends waist-to-height ratio alongside BMI as a practical measure of central fat, with 0.5 as the top of the healthy range for adults.
Relative Fat Mass
men: 64 − (20 × height ÷ waist) · women: 76 − (20 × height ÷ waist) Woolcock and colleagues, Scientific Reports, 2018. A two-input estimate validated against DXA in the NHANES data set, where it tracked measured body fat more closely than BMI did.
  • This is an estimate from two measurements, not a measurement of your body composition. A DEXA or InBody scan measures it directly.
  • It is general information about training and body composition, not medical advice, and it does not assess or diagnose any condition.

More

  • Deficit Check Maintenance calories, a deficit band, and the protein floor. No date attached to a kilogram, because that is not a number anyone can honestly give you.
  • Strength Standards Turn a set of five into an estimated one-rep max, then see which of your three lifts is a tier behind the others.
  • Race Readiness Projects your running from a 5k, then shows what the target you picked leaves you for the eight stations. Usually less than people expect.
  • Programme Builder How many sessions your goal takes, how many need a coach, and whether the weeks you have are enough. It will tell you when they are not.
All tools

Get Started

Ready to begin?
Book today.

Soho Personal Training • UNTIL, 111 Charing Cross Road, London WC2H 0DT

Enquire

Appointments typically available within 1–2 weeks