Pregnancy Weight Gain Calculator

Enter your pre-pregnancy weight (kg): Enter your height (cm):

🤰 Pregnancy Weight Gain Calculator

Intro

During pregnancy, weight gain is not only natural but also essential for the healthy growth of your baby. However, the amount of weight you should gain depends on your pre-pregnancy body mass index (BMI) and overall health. Our Pregnancy Weight Gain Calculator helps expectant mothers determine the recommended weight gain range throughout each trimester.

Instead of guessing or relying on general advice, this calculator provides a personalized recommendation based on medical guidelines. It is a useful tool for mothers-to-be who want to maintain a healthy pregnancy, avoid complications, and track their progress with confidence.

Formula / Working

The Pregnancy Weight Gain Calculator works by combining two key factors:

Pre-pregnancy BMI – calculated as weight (kg) ÷ height (m²).
Medical recommendations – from the Institute of Medicine (IOM) guidelines.

Recommended total weight gain ranges:

Underweight (BMI < 18.5): 28–40 lbs (12.5–18 kg)
Normal weight (BMI 18.5–24.9): 25–35 lbs (11.5–16 kg)
Overweight (BMI 25–29.9): 15–25 lbs (7–11.5 kg)
Obese (BMI ≥ 30): 11–20 lbs (5–9 kg)

The calculator also divides this into trimester-based targets. For example, in the first trimester, most women gain only 1–5 lbs, while the majority of weight gain occurs during the second and third trimesters.

Step-by-Step Usage

Using the Pregnancy Weight Gain Calculator is simple:

Enter your pre-pregnancy weight and height.
The calculator will compute your BMI.
Select your current trimester or week of pregnancy.
Click on the Calculate button.
Instantly see your recommended weight gain range and track whether you are on target.

This easy process ensures you receive accurate results tailored to your body type and pregnancy stage.

Examples

Example 1:
Emma was 55 kg and 162 cm tall before pregnancy. Her BMI is 20.9 (normal). The calculator recommends a total gain of 11.5–16 kg. By her second trimester, she should have gained around 4–5 kg.
Example 2:
Nadia weighed 80 kg at 165 cm (BMI 29.4 – overweight). The calculator suggests a total gain of 7–11.5 kg. At 20 weeks, her healthy range is about 3–4 kg gained so far.

These examples highlight how the tool personalizes guidance for different body types, making pregnancy tracking more accurate.

FAQs

Q1: Why is pregnancy weight gain important?
A: Healthy weight gain supports your baby’s growth and reduces risks of complications like low birth weight or preterm delivery.

Q2: What if I gain too much or too little weight?
A: Both can increase risks. Too much weight may lead to gestational diabetes, while too little can affect your baby’s development. Always consult your doctor.

Q3: Can I use this calculator at any stage of pregnancy?
A: Yes, it works from the first trimester until delivery, adjusting recommendations accordingly.

Q4: Does the calculator replace medical advice?
A: No, it’s a helpful guide, but your doctor should always provide the final recommendations based on your health.

Q5: Is exercise safe during pregnancy?
A: Moderate exercise is usually safe and beneficial, but always check with your healthcare provider before starting or continuing a fitness routine.