Pregnancy Weight Gain Calculator

Find your recommended pregnancy weight gain range from pre-pregnancy BMI.

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Pregnancy Weight Gain Calculator: The Complete Guide

See how much weight gain is recommended during pregnancy. Enter your pre-pregnancy weight and height to get your BMI and the recommended total gain range for a single-baby pregnancy.

Who the Pregnancy Weight Gain Calculator is for

Expectant parents who want evidence-based weight-gain targets for their starting BMI.

How to use the Pregnancy Weight Gain Calculator

  1. Type your values into the fields above — pick your currency or units where the calculator offers them.
  2. Results update automatically as you type; there's no submit button and nothing is sent to a server.
  3. Adjust any input to compare scenarios, then copy the result with a single click.

How it works

Recommendations follow Institute of Medicine guidelines by pre-pregnancy BMI: underweight 12.5–18 kg, normal 11.5–16 kg, overweight 7–11.5 kg, and obese 5–9 kg for a single baby.

Features

  • Pre-pregnancy BMI
  • Recommended gain range
  • IOM guidelines
  • Metric or imperial

Healthy weight gain in pregnancy

Recommended pregnancy weight gain depends on your weight before pregnancy: people who start at a lower BMI are advised to gain more, and those who start higher, less. These Institute of Medicine ranges are for a single baby; twins need more. Your provider will personalise the target to your health and pregnancy.

Frequently Asked Questions

Are these ranges for twins too?

No — these are single-baby guidelines. Twin pregnancies have higher recommended gains, so follow your provider's specific advice.

What if I gain outside the range?

Gaining a bit more or less isn't necessarily a problem, but large deviations are worth discussing with your provider to support a healthy pregnancy.

Is this calculator free and private?

Yes. It's completely free with no signup, and every calculation runs locally in your browser, so your numbers never leave your device.

BMI Calculator

Calculate your Body Mass Index from height and weight, with your category and healthy range.

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