How do I calculate pre-pregnancy BMI from height and weight?
BMI = pre-pregnancy weight (kg) ÷ height² (m²). U.S. categories are under 18.5, 18.5–24.9, 25.0–29.9, and 30 or higher.
Health & fitness
Pregnancy BMI calculator
Calculate pre-pregnancy BMI from weight and height using CDC adult BMI categories.
- Metric and imperial units
- Instant updates as inputs change
- Data is calculated in this browser only
Results update as you type
Pre-pregnancy BMI20.7
U.S. reference- CDC category
- Healthy weight range
- Healthy BMI reference
- 18.5–24.9
Pregnancy weight-gain guidance also depends on pre-pregnancy BMI and singleton versus twin pregnancy.
Calculation notes
Understand the Pregnancy BMI calculator
Calculates BMI from pre-pregnancy weight and height, then applies CDC adult BMI categories.
What is the pre-pregnancy BMI for 132 lb at 5 ft 7 in?
At 132 lb and 5 ft 7 in, pre-pregnancy BMI is about 20.7, within the CDC healthy-weight range.
Should pregnancy BMI use current weight or pre-pregnancy weight?
- Use pre-pregnancy—not current pregnancy—weight.
- This BMI category is an input to total pregnancy weight-gain guidance.
What are the limits of using BMI during pregnancy?
- BMI does not describe body composition or individual pregnancy risk.
- Discuss unusual weight change, twins, or medical conditions with prenatal care staff.
Content and calculation reviewed: