About This Pregnancy Weight Gain Calculator

Healthy weight gain during pregnancy varies by pre-pregnancy BMI. The Institute of Medicine provides ranges: underweight women typically gain more, while overweight/obese women gain less. This calculator uses your BMI to provide total recommended gain and weekly targets. Keep a gentle pace, consult your provider for personalized guidance, and track with our Pregnancy Calendar.

BMI Categories and Recommended Weight Gain:

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 kg)
Obese (BMI ≥ 30): 11-20 lbs (5-9 kg)

Related Pregnancy Information

While tracking your weight gain, you might also be curious about other aspects of your pregnancy, such as predicting your baby's gender. While the most accurate methods are medical (ultrasound and NIPT), there are several traditional methods people enjoy for fun:

Ultrasound: 95-99% accurate at 18-20 weeks
NIPT: 99% accurate from 9 weeks
Nub Theory: 75% accurate at 12-14 weeks

Chinese Gender Chart: Traditional method
Shettles Method: Based on timing of conception
Heart Rate Method: Based on fetal heart rate

For detailed information about these methods, including accuracy rates and how they work, visit Baby Gender Prediction Methods.

Frequently Asked Questions

What BMI categories are used?

The Institute of Medicine defines four pre-pregnancy BMI categories: Underweight (BMI < 18.5), Normal weight (BMI 18.5-24.9), Overweight (BMI 25-29.9), and Obese (BMI ≥ 30). These categories determine the recommended weight gain ranges during pregnancy.

Is weight gain the same in every trimester?

No, weight gain patterns vary by trimester. Most women gain 1-4 pounds in the first trimester, and then about 1 pound per week in the second and third trimesters. The rate of gain may slow in the final weeks as the baby drops into position.

What if I'm underweight or overweight?

If you're underweight, you'll need to gain more weight (28-40 pounds) to support healthy fetal development. If you're overweight or obese, you'll need to gain less (11-20 or 15-25 pounds respectively). Your healthcare provider can provide personalized guidance based on your specific situation.

When to contact your doctor about weight changes?

Contact your healthcare provider if you experience rapid weight gain (more than 3-5 pounds in a week), sudden weight loss, or if your weight gain significantly deviates from the recommended range. These could indicate complications that need medical attention.

Can I lose weight during pregnancy?

For women who are overweight or obese, some healthcare providers may approve modest weight loss in the first trimester. However, weight loss is generally not recommended during pregnancy as the developing baby needs adequate nutrition. Always consult with your healthcare provider before attempting to lose weight during pregnancy.

Pregnancy Weight Gain Calculator — Healthy Targets by Week