Pregnancy Calorie Calculator
Estimates daily caloric requirements by trimester based on ACOG guidelines and pre-pregnancy BMI. Supports fetal development monitoring.
About
Caloric needs during gestation shift dynamically to support placental growth, amniotic fluid production, and fetal development. This calculator utilizes the Mifflin-St Jeor equation for Basal Metabolic Rate (BMR) and applies specific surpluses defined by the American College of Obstetricians and Gynecologists (ACOG). Accuracy in energy intake is critical here; insufficient energy can compromise fetal growth restrictions, while excessive surplus increases the risk of gestational diabetes and macrosomia.
The calculation accounts for the three distinct phases of gestation. The First Trimester typically requires no additional caloric load compared to baseline maintenance. The Second and Third Trimesters introduce specific metabolic demands requiring controlled increases. This tool also considers pre-pregnancy Body Mass Index (BMI) to contextualize weight gain trajectories.
Formulas
The baseline energy expenditure is calculated using the Mifflin-St Jeor equation for women:
Where w is weight in kg, h is height in cm, and a is age in years. The total requirement E is adjusted by activity factor γ and trimester surplus S:
The variable S assumes values of 0 (T1), 340 (T2), or 450 (T3) kcal.
Reference Data
| Pre-Pregnancy BMI | Category | Recommended Total Gain (lbs) | Recommended Total Gain (kg) |
|---|---|---|---|
| < 18.5 | Underweight | 28 - 40 | 12.5 - 18 |
| 18.5 - 24.9 | Normal Weight | 25 - 35 | 11.5 - 16 |
| 25.0 - 29.9 | Overweight | 15 - 25 | 7 - 11.5 |
| ≥ 30.0 | Obese | 11 - 20 | 5 - 9 |