Calculadora de IMC na Gravidez
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
IMC = peso / altura²
About this calculator
The Pregnancy BMI Calculator estimates the Body Mass Index (BMI) using weight and height recorded before pregnancy. BMI is calculated by dividing weight (in kg) by height squared (in meters). This index serves as an initial reference for classifying the nutritional status of the pregnant woman, helping to plan appropriate weight gain during pregnancy.
How it works: simply enter your pre-pregnancy weight and height. The calculator applies the formula BMI = weight / height² and displays the numerical result along with the classification (underweight, normal, overweight, or obese) based on WHO ranges. Note that this calculation only considers the pre-pregnancy period, as BMI is not recommended as a standalone indicator during pregnancy.
When to use? Ideally before pregnancy or at the beginning of prenatal care, so the doctor can set appropriate weight gain goals. It is also useful for women planning a pregnancy who want to assess their nutritional status. Cautions: BMI does not reflect body composition (muscle vs. fat) and does not replace individualized medical assessment. Pregnant women with high or very low BMI should receive differentiated nutritional follow-up.
Frequently asked questions
Is pregnancy BMI calculated with current weight or pre-pregnancy weight?
Pregnancy BMI should be calculated using pre-pregnancy weight, i.e., the weight you had before becoming pregnant. During pregnancy, weight gain is expected and BMI is no longer an accurate indicator.
What are the BMI ranges for pregnant women?
The ranges follow WHO classification: below 18.5 is underweight; 18.5 to 24.9 is normal; 25 to 29.9 is overweight; and above 30 is obese. For pregnant women, these ranges help determine recommended weight gain.
Can I use this calculator if I am already pregnant?
Yes, but only with your pre-pregnancy weight. If you are already pregnant, enter the weight you had before pregnancy to get the reference BMI. The result should not be used to evaluate your current weight.
Does pregnancy BMI replace a doctor's visit?
No. The calculator is only an informational tool. Prenatal care with a doctor or nutritionist is essential for a complete assessment of your and your baby's health.
What should I do if my BMI is outside the normal range?
Consult your doctor or nutritionist for personalized guidance. A low or high BMI may require special attention to diet and weight gain during pregnancy.