Pregnancy weight gain calculator
Enter your weight before pregnancy and your height to see the total gain that suits you and the weekly rate in the second and third trimesters.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter weight before pregnancy, height and pregnancy.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
BMI = weight ÷ (height in m)². One baby: under 18.5: 12.5 to 18 kg; 18.5 to 24.9: 11.5 to 16 kg; 25 to 29.9: 7 to 11.5 kg; 30 or more: 5 to 9 kg. Twins: 17 to 25, 14 to 23 and 11 to 19 kg.
Example
Inputs: Weight before pregnancy = 60 kg, Height = 165 cm, Pregnancy = One baby. Result: Recommended total gain: 11.5 to 16 kg; Pre-pregnancy BMI: 22; Category: Healthy weight.
Limits and caveats
- The guidelines are for adults; advice may differ for teenagers or with health conditions.
- The twin figures are provisional in the IOM report; your doctor’s advice comes first.
Questions about this tool
How much weight is gained in the first trimester?
The IOM assumes only 0.5 to 2 kg in the first trimester; the weekly rate applies from the second trimester.
Why is less gain advised at a higher BMI?
The body already has more reserves, and extra gain raises the risk of gestational diabetes, high blood pressure and a large baby.
Should I use my current weight?
No. Use your weight before or at the start of pregnancy, since the advice is based on it.