Pregnancy Weight Gain Calculator
Track recommended pregnancy weight gain based on pre-pregnancy BMI. Uses IOM (Institute of Medicine) guidelines with week-by-week targets and SVG weight curve.
Quick Calculator Get a fast estimate
kg
cm
kg
weeks
Weight Gain Status
Above Recommended
Gained So Far
7 kg
Expected Range (Wk 20)
3,8 – 5,3 kg
Pre-Pregnancy BMI
23,9
BMI Category
Normal Weight (BMI 18.5–24.9)
Total Recommended Gain
11.5 – 16 kg
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How Pregnancy Weight Gain is Calculated
The Institute of Medicine (IOM) guidelines recommend total weight gain based on your pre-pregnancy BMI. Normal weight women should gain 11.5–16 kg total, gaining approximately 0.42 kg/week in the 2nd and 3rd trimesters.
This calculator compares your actual weight gain against expected values for your current pregnancy week.
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kg
cm
wks
kg
Weight Gained
7.0 kg at week 20
BMI Category
Normal Weight
Recommended total
11.5–16 kg
Expected at wk 20
3.8–5.3 kg
Weight Gain Curve (IOM Normal Weight)
IOM Pregnancy Weight Gain Guidelines
| Pre-Pregnancy BMI | Category | Total Gain | 2nd/3rd Tri Rate |
|---|---|---|---|
| < 18.5 | Underweight | 12.5–18 kg | 0.44–0.58 kg/wk |
| 18.5–24.9 | Normal weight | 11.5–16 kg | 0.35–0.50 kg/wk |
| 25–29.9 | Overweight | 7–11.5 kg | 0.23–0.33 kg/wk |
| ≥ 30 | Obese | 5–9 kg | 0.17–0.27 kg/wk |
| Twin pregnancy (normal) | — | 16.8–24.5 kg | 0.6–0.7 kg/wk |
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Profile
kg
cm
IOM Recommended Total Gain
11.5 – 16 kg
BMI
23.9
Category
Normal Weight
Weekly Weight Log
wk
kg
+1.0 kg
wk
kg
+3.0 kg
wk
kg
+5.0 kg
wk
kg
+7.0 kg
Trimester Analysis
| Trimester | Weeks | Gain | IOM Target |
|---|---|---|---|
| 1st Trimester | 1–13 | 0.0 kg | 0.5–2 kg |
| 2nd Trimester | 14–27 | 6.0 kg | ~4.6–6.4 kg |
| 3rd Trimester | 28–40 | 0.0 kg | ~4.6–6.4 kg |
| Total Gained | 7.0 kg | 11.5–16 kg |
Frequently Asked Questions
IOM guidelines by BMI: Normal weight (BMI 18.5–24.9): 11.5–16 kg. Underweight: 12.5–18 kg. Overweight: 7–11.5 kg. Obese: 5–9 kg. Twin pregnancies: 16.8–24.5 kg.
In the first trimester, total gain is 0.5–2 kg. In the 2nd and 3rd trimesters, normal weight women gain approximately 0.35–0.50 kg/week.
This calculator uses the standard IOM guidelines. Always consult your obstetrician, midwife, or healthcare provider for personalised advice during pregnancy.