Skip to main content
Calkulon

How to Calculate Pregnancy Weight Gain

What is Pregnancy Weight Gain?

Recommended pregnancy weight gain is based on pre-pregnancy BMI, as established by the Institute of Medicine (IOM) 2009 guidelines. Gaining too little weight increases the risk of low birth weight; gaining too much increases risks of gestational diabetes, caesarean delivery, and postpartum weight retention.

Step-by-Step Guide

  1. 1IOM recommends different total weight gain ranges based on pre-pregnancy BMI
  2. 2First trimester gain: typically 1.1–2.2 kg (0.5–1 kg/month)
  3. 3Second and third trimester: 0.2–0.5 kg/week depending on BMI category

Worked Examples

Input
Pre-pregnancy BMI 22 (normal weight)
Result
Recommended gain: 25–35 lbs total

Frequently Asked Questions

What is Pregnancy Weight?

Recommended pregnancy weight gain is based on pre-pregnancy BMI, as established by the Institute of Medicine (IOM) 2009 guidelines. Gaining too little weight increases the risk of low birth weight; gaining too much increases risks of gestational diabetes, caesarean delivery, and postpartum weight retention

How accurate is the Pregnancy Weight calculator?

The calculator uses the standard published formula for pregnancy weight. Results are accurate to the precision of the inputs you provide. For financial, medical, or legal decisions, always verify with a qualified professional.

What units does the Pregnancy Weight calculator use?

This calculator works with kilograms, inches. You can enter values in the units shown — the calculator handles all conversions internally.

What formula does the Pregnancy Weight calculator use?

The calculator applies the standard formula for this type of calculation. See the 'How It Works' steps above for the detailed formula breakdown.

Ready to calculate? Try the free Pregnancy Weight Gain Calculator

Try it yourself →

Settings

PrivacyTermsAbout© 2026 Calkulon