Know your numbers, and what they cannot tell you
Body Numbers works out your BMI, body fat, waist ratios, resting calories and daily energy needs. Every result names the formula behind it and says where that formula stops being useful.
100,000+ downloads on Google Play. Free, and it works offline.
One number is never the whole picture
BMI was built to describe populations, not people. It cannot see muscle, bone or where you carry weight, so it reads a lean athlete and a sedentary person of the same height and weight exactly the same way. That is why the app runs several methods side by side and shows you where they disagree.
Three ways to estimate it
The US Navy circumference method, Relative Fat Mass and the Deurenberg equation, with healthy ranges by sex and age.
Waist to height, and roundness
Waist to height ratio and the Body Roundness Index, which see the fat distribution BMI misses entirely.
Resting and daily calories
Mifflin St Jeor for resting metabolic rate, your activity level for daily needs, and a macro split you can adjust.
BMI for age, done properly
Percentiles from the WHO 2007 growth reference rather than adult cut points, which do not apply to a growing child.
More from us
Three apps, three different jobs. This one answers the question today.
Weight Diary
Weight over time. You want to watch one number move, with the calculators alongside it.
Body Diary
The whole body over time: measurements, photos, several people, cloud backup. You measure more than weight and want the record kept and synced.
This is not medical advice. Body Numbers is a calculator. It does not diagnose, treat or monitor any condition, and no number it produces should replace a conversation with a doctor or a dietitian. If a result worries you, or if you are pregnant, unwell, or under eighteen, speak to a health professional.