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Calculation Machine

Pregnancy Weight Gain Calculator

Recommended gain by BMI and week.

Reviewed by the Calculation Machine team · How we check our maths

Your values

ⓘ Live results

Results
Recommended total gain
11.5–16 kg
Pre-pregnancy BMI
23.1
Expected gain by week 24
5.3–7.7 kg
Gained so far
7 kg
Status
On track

Quick answer

Recommended gain depends on pre-pregnancy BMI: 25–35 lb for normal weight, less if overweight.

Worked example

Worked example

Using the values the calculator loads with.

Inputs

  • Pre-pregnancy weight63 kg
  • Height165 cm
  • Current week24
  • Current weight70 kg

Result

  • Recommended total gain11.5–16 kg
  • Pre-pregnancy BMI23.1
  • Expected gain by week 245.3–7.7 kg
  • Gained so far7 kg
  • StatusOn track

How to use the Pregnancy Weight Gain Calculator

  1. 1Enter your pre-pregnancy weight and height.
  2. 2Enter your current week of pregnancy.
  3. 3Enter your current weight.

Frequently asked questions

Do twins change this?

Yes — recommended gain is roughly 17–25 kg for twins at normal BMI.

Is gaining slowly a problem?

Discuss any consistent deviation with your midwife or doctor.

About this calculator

How much weight gain is recommended

Recommended weight gain depends on your BMI before pregnancy. The Institute of Medicine guidance suggests 11.5–16 kg (25–35 lb) for a normal-weight BMI, more for underweight and less for overweight or obese starting weights. The calculator shows your range and where you are week by week.

Most gain happens in the second and third trimesters. In the first trimester, a total of 0.5–2 kg is typical, and some people lose a little because of nausea.

Keeping perspective

  • Weekly gains vary — look at the trend over several weeks.
  • Twin pregnancies have higher recommended ranges.
  • Your midwife or doctor may set a different target based on your health.

Sources

More questions

How much weight should I gain per week?

In the second and third trimesters, about 0.4 kg (1 lb) a week is typical for a normal starting BMI.

Where does the weight go?

Baby, placenta, amniotic fluid, extra blood and fluid, breast tissue and some fat stores.