Pregnancy Weight Gain Calculator - Calculator See


Pregnancy Weight Gain Calculator

Calculate recommended pregnancy weight gain targets based on pre-pregnancy BMI and gestational week, following Institute of Medicine (IOM) clinical guidelines.

Calculator Inputs

lbs
Weight before pregnancy.
in
Standing height (65 in = 5 ft 5 in).
wks
Gestational week.
Single or multiple pregnancy.

Calculated Results

Target Weight Gain to Date
11.5 - 14.0 lbs (at Week 20)
Pre-Pregnancy BMI 23.3 (Normal Weight)
Total Target Full-Term Gain 25.0 - 35.0 lbs
Weekly Rate (2nd & 3rd Trimester) 1.0 lb / week
Values calculate live as you adjust inputs.

About Pregnancy Weight Gain Calculator

The Pregnancy Weight Gain Calculator provides clinical weight targets based on pre-pregnancy Body Mass Index (BMI) and the Institute of Medicine (IOM) guidelines.

What is Pregnancy Weight Gain Calculator?

The Pregnancy Weight Gain Calculator provides clinical weight targets based on pre-pregnancy Body Mass Index (BMI) and the Institute of Medicine (IOM) guidelines.

How to Use This Calculator

  1. Enter pre-pregnancy weight and height.
  2. Select your current pregnancy week.
  3. Review target weight gain range to date and full-term recommendation.

The Mathematical Formula & Variables

Normal BMI (18.5-24.9) recommends 1-4 lbs in 1st trimester + ~1 lb/week thereafter

Step-by-Step Worked Example

Scenario: Woman at 5 ft 5 in (65 in) weighing 140 lbs (BMI 23.3) at week 20.

  1. 1st trimester gain: ~3 lbs.
  2. Weeks 13 to 20 (7 weeks at 1 lb/week): ~7 to 10 lbs.
  3. Expected gain at week 20 = 10 to 14 lbs.

Result: 11.5 - 14.0 lbs at Week 20

Frequently Asked Questions

Why is healthy pregnancy weight gain important?

Appropriate weight gain supports fetal development while reducing risks of gestational diabetes, preeclampsia, and Cesarean delivery.