# Pregnancy Weight Gain Calculator

> Compare current pregnancy weight gain with BMI- and pregnancy-type-based total and week-by-week reference ranges.

Page: https://askcalculators.com/calculator/pregnancy-weight-gain-calculator/
Definition: https://askcalculators.com/calculator/pregnancy-weight-gain-calculator/definition.json
JSON Schema: https://askcalculators.com/calculator/pregnancy-weight-gain-calculator/schema.json
Version: 2.0.0
Maintained by: AskCalculators (software project; not a credentialed reviewer)
Qualified review: pending. Automated checks do not establish professional approval.
Page status: Live
Review status: Pending

## Use
Open the calculator page and enter values. Query-string parameters can restore and bookmark a calculation.
Example: https://askcalculators.com/calculator/pregnancy-weight-gain-calculator/?unitSystem=imperial&pregnancyType=singleton&gestationalWeek=20&preWeightLb=141&currentWeightLb=152&feet=5&inches=5

## Inputs
- unitSystem: Units; type=select; required; default=imperial; values=imperial|metric
- pregnancyType: Pregnancy type; type=select; required; default=singleton; values=singleton|twins
- gestationalWeek: Current gestational week; type=number; required; default=20; min=0; max=42
- preWeightKg: Pre-pregnancy weight; type=number; required; default=64; min=25; max=300; showWhen=unitSystem:metric
- currentWeightKg: Current weight; type=number; required; default=69; min=25; max=350; showWhen=unitSystem:metric
- heightCm: Height; type=number; required; default=165; min=100; max=230; showWhen=unitSystem:metric
- preWeightLb: Pre-pregnancy weight; type=number; required; default=141; min=55; max=660; showWhen=unitSystem:imperial
- currentWeightLb: Current weight; type=number; required; default=152; min=55; max=770; showWhen=unitSystem:imperial
- feet: Height feet; type=number; required; default=5; min=3; max=8; showWhen=unitSystem:imperial
- inches: Height inches; type=number; required; default=5; min=0; max=11.9; showWhen=unitSystem:imperial

## Outputs
- currentGain: Current weight gain; format=text; primary
- expectedByWeek: Reference gain by current week; format=text
- totalRange: Reference total gain; format=text
- status: Comparison; format=text
- prePregnancyBmi: Pre-pregnancy BMI; format=number
- bmiCategory: Pre-pregnancy BMI category; format=text

## Formula
Reference ranges depend on pre-pregnancy BMI and singleton or twin pregnancy; expected-to-date gain interpolates first-trimester gain and later weekly rates.

## Rules
- Empty optional inputs are undefined, not zero.
- Hidden conditional inputs are ignored.
- Do not invent missing required inputs.

Notice: Pregnancy weight goals are individualized. Use prenatal-care guidance, especially for twins, significant symptoms, or rapid weight change.