Pregnancy Weight Gain Calculator by Week & BMI

Pregnancy Weight Gain Calculator

Enter your pre-pregnancy height and weight and the current pregnancy week — the calculator shows the recommended weight gain range based on your BMI.

Your measurements

Height

ft in

Pre-pregnancy weight

Pregnancy week

BMI & weight category

BMI: –

Recommended weight gain by week 20

	kg	lb
Min	–	–
Avg	–	–
Max	–	–

Estimated total weight by week 20

	kg	lb
Min	–	–
Avg	–	–
Max	–	–

Recommendations are based on pre-pregnancy BMI and standard obstetric guidelines. Results are estimates — consult your healthcare provider for personal advice.

Frequently asked questions about pregnancy weight gain

How does the pregnancy weight gain calculator work?

The calculator uses your pre-pregnancy height and weight to estimate BMI, then shows a recommended pregnancy weight gain range by week. The result is a guide, not a diagnosis.

How much weight should I gain during pregnancy?

Recommended weight gain depends mainly on your pre-pregnancy BMI and whether you are carrying one baby or multiples. Your maternity provider can interpret the range in the context of your health.

Is it normal to gain little weight in the first trimester?

Yes. Some people gain little weight in early pregnancy, especially with nausea or vomiting. Weight gain often becomes more noticeable in the second and third trimesters.

What if I gain more or less than the calculator recommends?

One result outside the range does not automatically mean something is wrong. Discuss sudden, very rapid, very low or concerning weight changes with your midwife, OB-GYN or healthcare provider.

Can I use this calculator instead of medical advice?

No. Pregnancy weight gain guidance is individual. This calculator gives an estimate and should not replace care from your healthcare provider.