Formula
Convert inches and pounds to metric units, calculate BMI, estimate BMR from sex, age, weight and height, then multiply by the activity factor.
US health reference
US BMI / Calorie Calculator
Estimate adult BMI, BMR and maintenance calories from height, weight, age, sex and activity level. This is not a medical diagnosis.
Estimated BMI
Enter values to calculate Calculation basis date: May 17, 2026. CDC adult BMI categories and Mifflin-St Jeor BMR estimate.Calculation Basis and Official Sources
Calculation basis date: May 17, 2026. Uses CDC adult BMI categories and a common BMR estimation equation.
Before changing diet, medication, treatment or exercise because of BMI or calorie estimates, check a qualified health professional.
Formula and Interpretation
How to read it
BMI is a screening category. It does not measure body fat, muscle mass, pregnancy status, blood pressure, blood glucose or clinical risk by itself.
This calculator and its examples are for general information and rough estimation only. They are not medical diagnosis, treatment advice, pregnancy care advice, nutrition advice, emergency guidance, legal advice, tax advice, insurance advice or any other professional advice.
Actual health, pregnancy and nutrition decisions can differ because of symptoms, age, pregnancy status, medical history, medication, clinical measurements, ultrasound results and a clinician's judgement. Use a qualified health professional or medical service before acting on the result.
Calcitda does not guarantee accuracy, completeness, currentness or suitability for your situation. To the fullest extent permitted by law, we disclaim liability for losses, damages, claims or decisions arising from use of, or reliance on, this page.
Before You Rely on the Result
Practical examples
Enter 68 inches and 165 lb to see the BMI category and estimated maintenance calories.
Switch activity level to compare sedentary and moderate exercise assumptions.
Use the result as a conversation starter with a clinician, not as a diagnosis.
What this includes
- Adult BMI estimate
- BMR estimate
- Maintenance calorie estimate
What this does not include
- Body fat percentage, lab tests and clinical risk factors
- Children, teens, pregnancy and medical conditions
- Diet prescription or treatment advice
When to check official sources
Use a clinician, registered dietitian or medical service for health decisions, symptoms, pregnancy or disease management.