Track your weight gain during pregnancy and compare it with the recommended guidelines from the Institute of Medicine (IOM).
The Institute of Medicine (IOM) provides weight gain recommendations based on your pre-pregnancy BMI to ensure the health of both mother and baby.
Enter your measurements and current week to see your weight gain progress and recommendations.
From your first positive test to delivery day, here's a complete guide to healthy pregnancy weight gain — with 2026 guidelines, a trimester‑by‑trimester breakdown, and practical nutrition advice.
The Institute of Medicine (IOM) and the American College of Obstetricians and Gynecologists (ACOG) recommend weight gain ranges based solely on your pre‑pregnancy Body Mass Index (BMI).
| Pre‑pregnancy BMI | Total Recommended Gain | Weekly Gain (2nd & 3rd Trimester) |
|---|---|---|
| Underweight (< 18.5) | 28‑40 lbs (12.5‑18 kg) | ~1 lb (0.5 kg) |
| Normal weight (18.5 – 24.9) | 25‑35 lbs (11.5‑16 kg) | ~1 lb (0.4 kg) |
| Overweight (25.0 – 29.9) | 15‑25 lbs (7‑11.5 kg) | ~0.6 lb (0.3 kg) |
| Obese (≥ 30.0) | 11‑20 lbs (5‑9 kg) | ~0.5 lb (0.2 kg) |
A gain of 1.1–4.4 lb (0.5–2 kg) is expected regardless of starting BMI.
Guidelines are different for multiple pregnancies. Check the dedicated section below for specific targets.
To visualize your weekly progress, you might track your weight and compare it to the recommended target range. (Your healthcare provider can help you set specific weekly targets based on your starting BMI.)
| Gestational Week | Recommended Cumulative Gain | Your Weight (Example) |
|---|---|---|
| 20 | ~10‑14 lbs | 12 lbs (on track) |
| 22 | ~12‑16 lbs | 14 lbs (on track) |
| 24 | ~14‑18 lbs | 15 lbs (slightly below) |
| 26 | ~16‑20 lbs | 18 lbs (on track) |
| 28 | ~18‑22 lbs | 20 lbs (on track) |
| 30 | ~20‑24 lbs | 23 lbs (on track) |
At full term, the extra pounds are distributed across several components. Bottom line: Only about 30‑35% of the weight you gain is the baby. The rest is a beautiful orchestration of supportive tissues and fluids.
Baby
7.5 lbs
3.4 kg
Maternal Fat
7.0 lbs
3.2 kg
Fluid Volume
4.0 lbs
1.8 kg
Blood
4.0 lbs
1.8 kg
Uterus
2.0 lbs
0.9 kg
Breasts
2.0 lbs
0.9 kg
Amniotic Fluid
2.0 lbs
0.9 kg
Placenta
1.5 lbs
0.7 kg
*Table adapted from March of Dimes via Valley Medical Center*
Weight gain is not about eating everything in sight; it’s about nutrient density. A standard prenatal vitamin covers most of these, but whole foods are irreplaceable.
Weeks 1-13
Extra Calories: None
Fetal growth is minimal. Nausea or food aversions may even cause a small loss – that’s normal as long as you stay hydrated and take your prenatal vitamin.
Weeks 14-26
Extra Calories: ~340/day
Baby’s organs develop rapidly, placenta grows, and blood volume expands. Add calories from nutrient-dense foods.
Weeks 27-40
Extra Calories: ~450/day
Baby gains most of its birth weight, plus fluid retention peaks. Near the end, weight gain may plateau or drop slightly.
| Key Nutrient | Daily Goal | Best Food Sources |
|---|---|---|
| Folic Acid / Folate | 600‑800 mcg | Leafy greens, lentils, fortified cereals, oranges |
| Iron | 27 mg | Red meat, spinach, lentils, fortified cereals |
| Calcium | 1,000 mg | Milk, yogurt, cheese, leafy greens, fortified plant milks |
| Protein | 70‑100 g | Meat, poultry, fish, eggs, legumes, paneer, nuts |
| DHA (Omega‑3) | 200‑300 mg | Fatty fish (salmon, sardines), walnuts, chia seeds |
| Vitamin D | 600 IU | Sunlight, fortified milk, eggs, fatty fish |
| Iodine | 220 mcg | Iodized salt, dairy, eggs, seafood |
| Fluids | ~10 cups (2.4 L) | Supports increased blood volume and amniotic fluid |
A large 2025 meta‑analysis of 1.6 million women found that 68% of pregnancies had weight gain outside the healthy range. Staying within your target range significantly reduces health risks for both you and your baby.
Because you’re nourishing two (or more) babies, the weight gain recommendations are higher.
| Pre‑pregnancy BMI | Total Gain (Twins) |
|---|---|
| Normal weight | 37‑54 lb (17‑25 kg) |
| Overweight | 31‑50 lb (14‑23 kg) |
| Obese | 25‑42 lb (11‑19 kg) |
*Source: Institute of Medicine. No official guidelines exist for quadruplets or higher.
Calculate your pre‑pregnancy BMI (use an online calculator or ask your provider).
Find your target range in the official guidelines table above.
Weigh yourself weekly – at the same time of day, on the same scale, wearing similar clothing.
Focus on nutrient‑dense foods: lean protein, whole grains, fruits, vegetables, dairy, and legumes.
Stay hydrated – water, milk, and soups help manage fluid needs.
Talk to your provider if you’re gaining too quickly or too slowly – they can help you adjust without dieting.
Note after delivery: You’ll lose about 10‑15 lb right away (baby, placenta, amniotic fluid). The remaining weight usually comes off gradually with breastfeeding and healthy habits.
Explore more tools in the Pregnancy category