Free calculator
BMI & Ideal Weight Calculator
Body mass index, ideal body weight, and the weight range that corresponds to a healthy BMI at your height — with an honest account of what each number can and can't tell you.
Only affects ideal body weight
BMI
25.8
Overweight
Ideal body weight
161 lb
Devine formula
Where that sits
15
25
40
Body Metrics
Population estimates
BMI
25.8
Category
Overweight
Healthy range (BMI 18.5–24.9)
129 lb – 174 lb
Ideal body weight
161 lb
BMI is a population statistic, not a diagnosis. It uses only height and weight, so it cannot tell muscle from fat and reads high for muscular people and low for people who have lost muscle. The Devine formula only credits height above 5 feet and was designed for medication dosing, not as a target.
How this is calculated
BMI is weight in kilograms divided by height in metres squared. The healthy band is 18.5 to 24.9, and the range shown is simply that band converted back into weight at your height.
Ideal body weight uses the Devine formula: 50 kg for men or 45.5 kg for women, plus 2.3 kg per inch above 5 feet.
Both are population statistics. BMI cannot tell muscle from fat, and Devine was written in 1974 for medication dosing rather than as a target to aim at. They are context for a conversation with a clinician, not a verdict.
Optional, and off by default
Food Loops can show BMI alongside your weight chart if you want it, under Body Metrics Display in settings. It stays off unless you turn it on — for plenty of people the number causes more harm than it prevents.
Read the guide →Not medical advice. These calculators are for information and education only. The formulas are population estimates and cannot account for your individual circumstances. Talk to a qualified healthcare professional before making changes to your diet, particularly if you have a medical condition or are pregnant. See the full disclaimer.