Pregnancy Weight Gain Calculator

Enter your height and pre-pregnancy weight to find your BMI category, then see the total weight-gain range recommended for that category — plus a typical range so far for your current week. These are population guidelines for general information, not a target to chase.

Height (cm)Pre-pregnancy weight (kg)Current weekCurrent weight (kg)

I’m expecting twins

General information only, not medical advice. These are population ranges; your healthy gain may differ. Discuss your weight and your baby’s growth with your healthcare provider.

How it works

Recommended pregnancy weight gain is based on your pre-pregnancy body-mass index (BMI), using the widely used Institute of Medicine ranges (also reflected in Health Canada guidance). Lower starting BMI generally means a higher recommended gain, and a higher starting BMI a lower one.

Most gain happens in the second and third trimesters at a fairly steady weekly rate, after very little in the first trimester. We use that pattern to estimate a typical cumulative range for your current week, and — if you add your current weight — compare it to where you are. Your own provider’s advice always comes first.

Frequently asked questions

How much weight should I gain in pregnancy? +

It depends on your pre-pregnancy BMI. A common guide is about 11.5–16 kg (25–35 lb) for a normal-weight start, more if you began underweight and less if you began overweight or with obesity. Your provider may suggest a different range for you.

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

Yes. Many people gain very little — or even lose a little to nausea — in the first 13 weeks. Most pregnancy weight gain happens steadily through the second and third trimesters.

What if I’m gaining faster or slower than the range? +

A single reading isn’t the whole story — trends matter more than one number, and everyone is different. Bring any concern about your weight or your baby’s growth to your provider, who can see your full picture.

Are the ranges different for twins? +

Yes — recommended gain is higher for twins. This tool switches to twin ranges when you tick the box, but firm ranges aren’t defined for an underweight start, so always confirm with your provider.