Body Mass Index (BMI) Calculator
Body Mass Index (BMI) Calculator by NIVITA HUF. Model scenarios, review calculations, explore detailed breakdowns and export results. Useful free planning tool.
Set your assumptions
Update the values to calculate your scenario.
Your calculation
Results update as you enter information.
JavaScript is required for interactive calculations.
How this calculator works
BMI = mass(kg)/height(m)². BMR follows Mifflin–St Jeor. TDEE = BMR × activity factor. Body fat follows US Navy circumferences (cm).
Important assumptions
General educational estimates only; BMI and body-fat formulas are imperfect and do not diagnose health. TDEE and fluid needs vary by activity, climate, pregnancy, medications and medical conditions. The fluid estimate uses 35 mL/kg as a simple planning assumption; consult a clinician where needed.
About the Body Mass Index (BMI) Calculator
What inputs are needed for the Body Mass Index (BMI) Calculator?
The calculator supports Weight (kg); Height (cm); Age (years); Formula sex parameter; Activity multiplier; Waist circumference (cm). You can change each applicable input and immediately recalculate.
How does the Body Mass Index (BMI) Calculator calculate its results?
BMI = mass(kg)/height(m)². BMR follows Mifflin–St Jeor. TDEE = BMR × activity factor. Body fat follows US Navy circumferences (cm).
Can I save or share my calculation?
Yes. Use Export CSV for the results table, Copy results for a summary, Share scenario for an input-preserving link, or Print to keep a copy. No sign-in is needed.
Are calculator results guaranteed?
No. Calculations depend on the values entered and the assumptions shown. Financial products and regulatory rules can change, and investment projections do not guarantee returns.