Free Pregnancy Weight Gain Calculator Tool – Calculate Healthy Weight Gain

Pregnancy Weight Gain Calculator

Understand healthy weight gain targets based on your pre-pregnancy BMI and current week. Perfect for sharing results with midwives, OBs, or a pregnancy journal.

Evidence-Based
lbs
in
wk

Recommended Weight Gain

BMI (Pre-Pregnancy)
BMI Category
Total Gain Range
Expected Gain So Far

How Much Weight Should You Gain?

Healthy weight gain differs depending on where you started and how far along you are. This calculator uses Institute of Medicine (IOM) guidelines to provide personalized ranges.

Recommended Gain by BMI

Underweight (BMI < 18.5)

28–40 lbs total (avg 1 lb/week in 2nd & 3rd trimesters).

Normal (BMI 18.5–24.9)

25–35 lbs total. Focus on steady weekly gain.

Overweight (BMI 25–29.9)

15–25 lbs. Prioritize nutrient-dense meals.

Obese (BMI ≥ 30)

11–20 lbs. Work closely with your provider.

Tips for Balanced Pregnancy Nutrition

  • Eat every 3–4 hours to keep blood sugar stable and manage nausea.
  • Anchor meals with protein, healthy fats, and complex carbs.
  • Stay hydrated—aim for 80+ ounces of water per day.
  • Discuss supplements (prenatal vitamins, DHA, iron) with your provider.
  • Track weight gain on the same scale each week for consistency.

Frequently Asked Questions

Can I switch between pounds and kilograms?

This demo uses U.S. units. For metric, convert inputs beforehand: 1 kg = 2.205 lb, 1 inch = 2.54 cm.

What if my weight gain is outside the range?

Bring your log to prenatal visits. Providers consider overall health, appetite, activity, and baby’s growth scans.

Does this account for multiples?

Twin and triplet pregnancies often have higher recommended gain. Talk with your care team for personalized goals.