Pregnancy Weight Gain Calculator: Healthy Range by Week and BMI
Enter your height, weight before pregnancy and the current week to see the recommended total gain and where you should be now.
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Recommended total gain
11.5–16kg
Normal BMI- BMI before pregnancy
- 22 kg/m²
- Gain by this week
- 2.9–5.5 kg
- Weekly gain after week 13
- 0.35–0.5 kg/week
An estimate for general information, not medical advice. Follow your doctor's advice on weight in pregnancy.
IOM 2009 ranges. Indian guidance has long cited about 10–12 kg for a normal BMI; ask your doctor.
Week by week
| Week | Gain (kg) | Your weight (kg) |
|---|---|---|
| 4 | 0.2–0.6 | 55.2–55.6 |
| 8 | 0.3–1.2 | 55.3–56.2 |
| 12 | 0.5–1.8 | 55.5–56.8 |
| 13 | 0.5–2.0 | 55.5–57.0 |
| 16 | 1.5–3.5 | 56.5–58.5 |
| 20 | 2.9–5.5 | 58.0–60.5 |
| 24 | 4.3–7.5 | 59.4–62.5 |
| 28 | 5.8–9.5 | 60.8–64.5 |
| 32 | 7.1–11.5 | 62.1–66.5 |
| 36 | 8.5–13.5 | 63.5–68.5 |
| 40 | 9.9–15.5 | 65.0–70.5 |
How to use
- Enter your height and your weight before pregnancy.
- Enter how many weeks pregnant you are, and your weight now if you want a comparison.
- Read your total range, this week's range and the week-by-week table.
Good to know
Ranges follow the US Institute of Medicine (2009) by pre-pregnancy BMI: underweight (below 18.5) 12.5–18 kg, normal (18.5–24.9) 11.5–16 kg, overweight (25–29.9) 7–11.5 kg, obese (30 and above) 5–9 kg. For twins: 17–25, 14–23 and 11–19 kg (no range set for underweight).
Most gain happens after the first trimester. The first 13 weeks usually add only 0.5–2 kg; after that the guide is about 0.35–0.5 kg a week for a normal BMI (0.44–0.58 underweight, 0.23–0.33 overweight, 0.17–0.27 obese).
India note: there is no separate national BMI-based range yet; Indian guidance has long cited an average gain of about 10–12 kg for women of normal weight, and ICMR began a national study in 2025 to build India-specific ranges. Asian BMI cut-offs are lower (overweight from 23), so ask your doctor which range applies to you. Never diet to lose weight in pregnancy without medical advice.
Questions
How much weight should I gain in pregnancy?
It depends on your BMI before pregnancy. For a normal BMI the IOM range is 11.5–16 kg in total.
How much weight gain is normal in the first trimester?
About 0.5–2 kg. Some women lose a little because of nausea, which is usually fine; tell your doctor if you cannot keep food down.
I have gained more than the range. What should I do?
Do not start a diet on your own. Talk to your doctor or dietitian about food choices and safe activity such as walking.
Is the range different for twins?
Yes, it is higher: 17–25 kg for a normal BMI. Twin pregnancies need closer medical follow-up.
Is my data saved?
No. Everything is calculated on your device.