Pregnancy Weight Gain Calculator

Calculate recommended pregnancy weight gain based on your pre-pregnancy BMI. Track your weight gain throughout pregnancy using IOM guidelines.

Weight Gain Status

Current Gain

10.0 lbs

Within recommended range

Pre-pregnancy BMI23.3 (Normal Weight)
Recommended at Week9.0 lbs
Total Recommended25-35 lbs

Pregnancy Details

weeks
142

Measurements

Weight Gain Progress

Week 20 of 4010.0 lbs gained

Your Gain

10.0 lbs

Expected

9.0 lbs

Total Goal

25-35

Weight Gain Projection

Shaded area shows recommended weight range throughout pregnancy

IOM Weight Gain Guidelines

Pre-pregnancy BMITotal Gain (lbs)Weekly Rate (2nd/3rd)
Underweight (<18.5)28-40 lbs1.0-1.3 lbs
Normal (18.5-24.9)25-35 lbs0.8-1.0 lbs
Overweight (25-29.9)15-25 lbs0.5-0.7 lbs
Obese (30+)11-20 lbs0.4-0.6 lbs

Where Does Pregnancy Weight Go?

Baby

7-8 lbs

Placenta

1-2 lbs

Amniotic Fluid

2 lbs

Uterus

2 lbs

Breast Tissue

2 lbs

Blood Volume

4 lbs

Body Fluids

4 lbs

Fat Stores

5-9 lbs

Quick Answer

Recommended pregnancy weight gain depends on pre-pregnancy BMI. Normal BMI: gain 25-35 lbs. Underweight: 28-40 lbs. Overweight: 15-25 lbs. Obese: 11-20 lbs. Most gain occurs in 2nd and 3rd trimesters.

Key Facts

  • Weight gain based on pre-pregnancy BMI
  • Normal BMI: gain 25-35 lbs total
  • Little gain in first trimester (1-4 lbs)
  • About 1 lb/week in 2nd and 3rd trimesters
  • Twins: add 10-15 lbs to recommendations
  • Excessive gain increases complications

Frequently Asked Questions

Weight gain depends on your pre-pregnancy BMI. Underweight (BMI <18.5): 28-40 lbs. Normal weight (BMI 18.5-24.9): 25-35 lbs. Overweight (BMI 25-29.9): 15-25 lbs. Obese (BMI 30+): 11-20 lbs. Twin pregnancies require more weight gain.
Most women gain little weight in the first trimester (0-4 lbs). Weight gain picks up in the second trimester with about 1 lb per week. Some women may lose weight early due to morning sickness, which is usually not concerning.
Excess weight gain increases risk of gestational diabetes, high blood pressure, larger baby (making delivery harder), and difficulty losing weight postpartum. It doesn't harm the baby directly but can complicate pregnancy and delivery.
Insufficient weight gain may increase risk of preterm birth and low birth weight baby. Talk to your healthcare provider about calorie-dense, nutritious foods. Some women need help managing nausea to eat adequately.
Baby: 7-8 lbs. Placenta: 1.5 lbs. Amniotic fluid: 2 lbs. Uterus growth: 2 lbs. Breast tissue: 2 lbs. Blood volume: 4 lbs. Body fluids: 4 lbs. Fat stores: 5-9 lbs (for breastfeeding and energy).

Medical Disclaimer

This calculator is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider before making any health-related decisions.