Pregnancy Weight Gain Calculator
Healthy pregnancy weight gain depends on your weight before pregnancy. Enter your details to see your recommended total gain and a healthy target for the week you’re in, based on IOM guidelines.
Pregnancy Weight Gain Calculator
Healthy pregnancy weight gain depends on your weight before pregnancy. Enter your details to see your recommended total gain and a healthy target for the week you’re in, based on IOM guidelines.
Informational only — not medical advice or a diagnosis. Every pregnancy and cycle is different, and these results are estimates. Always consult your OB-GYN or midwife.
- Below pace
- On track for now
- Above pace
You're tracking above the recommended gain for week 20. It's worth discussing your weight gain with your OB-GYN.
- Pre-pregnancy BMI
- 23.9 (Normal weight)
- Recommended by week 20
- 3–5.2 kg
- You've gained so far
- 6 kg
Ranges follow Institute of Medicine (IOM) guidance for single pregnancies and depend on your starting BMI. Always confirm your targets with your OB-GYN.
This is an educational estimate, not medical advice. Consult a qualified professional. For pregnancy and cycle decisions, follow your OB-GYN — guidance reflects the American College of Obstetricians and Gynecologists (ACOG).
Save & share your result
How much weight should you gain?
The Institute of Medicine (IOM) bases its recommendations on your pre-pregnancy body mass index (BMI). For a single baby the guidelines are: 28–40 lb (12.5–18 kg) if you were underweight, 25–35 lb (11.5–16 kg) if a healthy weight, 15–25 lb (7–11.5 kg) if overweight, and 11–20 lb (5–9 kg) if obese.
This calculator works out your pre-pregnancy BMI, shows your recommended total range, and estimates how much of that you should have gained by your current week.
Gaining at a healthy pace
Most weight gain happens in the second and third trimesters. In the first trimester, a gain of just 1–4.5 lb (about 0.5–2 kg) is typical. After that, a steady rate of roughly 0.5–1 lb per week is recommended for those who started at a healthy weight, and a little less if you began overweight.
The gauge above compares the weight you’ve gained so far with the healthy range for your week, so you can see whether you’re on track, a little behind, or ahead.
Why healthy gain matters
Gaining within the recommended range supports your baby’s growth while lowering the risk of complications such as gestational diabetes, high blood pressure, a very large or very small baby, and difficulties at delivery. It also makes it easier to return to a healthy weight afterwards.
These ranges are general guidance, not strict rules — and they differ for twins or other multiples. Your OB-GYN will track your gain at appointments and give you advice tailored to your pregnancy and health.
Frequently asked questions
How much weight should I gain during pregnancy?
It depends on your pre-pregnancy BMI. IOM guidance suggests 25–35 lb for a healthy starting weight, 28–40 lb if underweight, 15–25 lb if overweight, and 11–20 lb if obese (for a single baby).
Is it normal to gain little in the first trimester?
Yes. Gaining only 1–4.5 lb in the first trimester is typical; nausea can even cause slight loss. Most pregnancy weight gain occurs in the second and third trimesters.
What if I gain more or less than recommended?
Week-to-week variation is normal, but consistently gaining well above or below the range is worth discussing with your OB-GYN, who can check that you and your baby are healthy.
Sources & references
Not medical advice. This result is an educational estimate from HealthyLifeStyles (Trusted Wellness), based on population formulas — not a diagnosis or treatment. Always consult a qualified healthcare professional about your health.
https://www.healthylifestyles.com/tools/pregnancy-weight-gain-calculator