BMI calculator
Work out your BMI and what it does and does not tell you before pregnancy. A screening number, not a verdict. Free and private.
Common questions
What does BMI tell me, and what does it miss?
BMI compares your weight with your height. It does not measure fat, muscle or fitness, and on its own it cannot tell you how healthy you are. Use it as a number to discuss with your clinician, not a verdict.
Can weight affect getting pregnant?
Weight is one of many things a clinician may talk about when you plan a pregnancy, along with your cycles, age and health history. BMI on its own cannot tell you your chances.
Is BMI used during pregnancy?
This calculator is for before pregnancy. Your weight is expected to change during pregnancy, so do not use this number to judge it; your maternity team follows your weight in their own way.
These calculators give general estimates for learning and planning, not medical advice. Talk to your clinician about your health.