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Pregnancy Weight Gain Calculator

Track your weekly weight gain progress based on medical guidelines

Enter Your Pregnancy Details

Please select your pregnancy week

Weight Gain Guidelines

General Guidelines

  • Gain 1-4 pounds during first trimester
  • Gain ~1 pound per week in 2nd & 3rd trimesters
  • Add ~300 calories per day for healthy weight gain

Important Notes

  • Individual needs may vary
  • Always consult your healthcare provider
  • Monitor weight gain regularly

Underweight (BMI < 18.5)

Single: 12.5-18 kg

Twins: Consult doctor

Normal (BMI 18.5-24.9)

Single: 11.5-16 kg

Twins: 17-25 kg

Overweight (BMI 25.0-29.9)

Single: 7-11.5 kg

Twins: 14-23 kg

Obese (BMI ≥ 30.0)

Single: 5-9 kg

Twins: 11-19 kg

Medical Disclaimer

This calculator provides estimates based on general medical guidelines. Individual recommendations may vary. Always consult with your healthcare provider for personalized advice.

How much weight you should gain during pregnancy depends on your pre-pregnancy BMI, not a single universal number. This calculator compares your current weight to the recommended range for your exact pregnancy week, based on CDC and Institute of Medicine guidelines, so you can see whether you're tracking within the expected pattern.
How to Use This Calculator
1

Select your weekPick your current pregnancy week from the trimester tabs.

2

Enter your heightUsed to calculate your pre-pregnancy BMI.

3

Enter pre-pregnancy weightThis sets your recommended gain range.

4

Enter current weightCompared against your target range for this week.

5

Select twins & calculateGet your BMI, weekly target, and delivery target.

Weight Gain Recommendations by BMI Category
Pre-Pregnancy BMI Single Baby Twins
Underweight (below 18.5)28–40 lbsConsult doctor
Normal weight (18.5–24.9)25–35 lbs37–54 lbs
Overweight (25.0–29.9)15–25 lbs31–50 lbs
Obese (30.0 and above)11–20 lbs25–42 lbs
Frequently Asked Questions
Is it normal to not gain weight in the first trimester?
Yes. Many women gain very little or nothing at all in the first trimester, especially if nausea affects eating. Weight gain typically picks up from the second trimester onward.
How much extra should I eat while pregnant?
Roughly no extra calories in the first trimester, about 340 extra calories a day in the second trimester, and about 450 extra calories a day in the third, according to CDC guidance.
What happens if I gain more than the recommended range?
Gaining above the range is linked to a higher chance of a larger baby and a more difficult delivery, but it's common and manageable with your provider's guidance rather than something to panic over.
Do twin pregnancies really need that much more weight gain?
Yes, twin pregnancies involve two babies, two placentas, and significantly more blood and fluid volume, which is why the recommended ranges sit noticeably higher than singleton pregnancies.
Should I try to lose weight if I'm overweight and pregnant?
No. Pregnancy is not the time for intentional weight loss, even with a higher starting BMI. The recommended ranges for overweight and obese categories are lower, not zero, because some gain is still necessary.

Want the full breakdown?

Read the complete guide on how much weight you should gain during pregnancy, or check your due date next.

Read the Guide Due Date Calculator