Mr Calcu | Track your pregnancy weight gain with confidence and stay on target for a healthier you and baby.

Calculate and monitor healthy pregnancy weight gain based on BMI and gestational age. Empower your journey and feel confident every step of the way.

Pregnancy Weight Gain Tracker

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Metric

Pre-pregnancy Weight (lbs)

Height (inches)

Gestational Age (weeks)

Current Weight (lbs)

Pregnancy Weight Gain Tracker Guidelines

You’ve got this! Follow these simple steps to stay on track:

How to Use the Calculator

Input your pre-pregnancy weight and height to calculate BMI
Enter your current gestational age in weeks
Log your current weight to compare with the recommended range
Track progress weekly to notice trends, not just one-time values
Refer to your healthcare provider for personalized guidance, especially in case of twins or medical conditions

Formula Recap:

BMI = weight (kg) / [height (m)]²

2nd/3rd Trimester Weekly Gain = (Target Total - Trimester 1 Gain) / Weeks 13–40

Pregnancy Weight Gain Tracker Description

Overview

Pregnancy weight gain plays a vital role in maternal and fetal health. Guidelines from the Institute of Medicine (IOM) and CDC help determine healthy ranges based on pre-pregnancy BMI.

Pro Tip: Monitoring weight trends over time is more accurate than relying on isolated readings.

Why It Matters

Improves chances of a full-term, healthy birth
Reduces maternal risks like hypertension or gestational diabetes
Supports optimal fetal development and birth weight

Understanding the Math

BMI Formula:

BMI = weight (kg) / [height (m)]²

Weekly Gain (2nd & 3rd Trimesters):

Recommended Weekly Gain = (Total Recommended Gain - First Trimester Gain) / Remaining Weeks

What’s Included in Pregnancy Weight Gain?

Fetus and placenta
Amniotic fluid
Increased blood volume
Breast tissue and maternal fat stores

Edge Case Considerations

High BMI (≥40): May require individualized targets under clinical supervision
Twin pregnancies: Increased caloric needs and weight gain (e.g., 37–54 lbs for normal BMI)
Preeclampsia or fluid retention: Can cause misleading rapid gains
Gestational diabetes: Weight gain may need stricter monitoring
Short stature: BMI may not fully reflect healthy body composition

Case Examples

Sarah (BMI 18.9)

Pre-pregnancy: 110 lbs at 5'4"
Current gestation: 24 weeks
Recommended cumulative gain by now: 14–18 lbs
Actual gain: 8 lbs — suggests risk for fetal growth restriction

Maya (BMI 30.7)

Pre-pregnancy: 190 lbs at 5'6"
Current gestation: 36 weeks
Recommended total gain: 11–20 lbs
Actual gain: 30 lbs — may increase risks of complications like macrosomia

Start using the calculator now to stay informed, empowered, and in control of your pregnancy journey!

Example Calculation

Recommended Weight Gain by BMI

Pre-pregnancy BMI	Recommended Total Gain	Rate of Gain (2nd/3rd trimester)	First Trimester Gain
Underweight (<18.5)	28–40 lbs	1.0–1.3 lbs/week	~5 lbs
Normal weight (18.5–24.9)	25–35 lbs	0.8–1.0 lb/week	~4.5 lbs
Overweight (25–29.9)	15–25 lbs	0.5–0.7 lb/week	~3.5 lbs
Obese (≥30)	11–20 lbs	0.4–0.6 lb/week	~2 lbs
Twin pregnancy (Normal BMI)	37–54 lbs	1.5 lbs/week	~6.5 lbs
Obese (≥40)	5–20 lbs (individualized)	0.3–0.5 lb/week	~1–2 lbs

Frequently Asked Questions

BMI is calculated using your weight and height before pregnancy. Use the formula: BMI = weight (kg) / height² (m²).

It helps detect nutritional issues, assess fetal growth, and minimize risks like preterm birth or high birth weight.

We recommend weekly tracking after the first trimester, especially from weeks 13 to 40.

Excessive gain may increase risks like gestational diabetes, C-section, and postpartum weight retention. Your provider can help tailor a nutrition plan.

Yes. For twins, normal-weight women should aim for 37–54 lbs total gain. The rate of gain is also higher.

Preeclampsia can cause rapid water retention and abnormal weight gain. Always inform your provider of sudden changes.

After the first trimester, most women gain about 0.5 to 1.0 pounds per week, depending on their BMI.