Pregnancy Calorie Calculator
Estimate your personalized daily energy needs across each trimester of pregnancy using the clinical Mifflin–St Jeor formula and ACOG nutritional guidelines.
Calculate Daily Caloric Needs
Enter your age, height, pre-pregnancy weight, activity level, and trimester.
The Mifflin–St Jeor Clinical Equation
BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) − 161
TDEE = BMR × Activity Multiplier
Pregnancy Daily Calories = TDEE + Trimester Addition
What This Calculator Cannot Do
- It cannot provide personalized medical dietary prescriptions for gestational diabetes or hyperemesis gravidarum.
- It does not account for multiple pregnancies (triplets/quadruplets) without clinician adjustment.
When to See a Doctor
Online calculators provide general estimates based on biological averages. Consult a healthcare provider (such as an OB/GYN or general practitioner) if you notice:
- Your periods suddenly become irregular after being consistent
- Your cycle is consistently shorter than 21 days or longer than 35 days
- Your period bleeding lasts longer than 7 days or is unusually heavy (soaking through a pad/tampon every hour)
- You experience severe, debilitating pelvic pain or cramping that disrupts daily life
- You experience bleeding between periods or after intercourse
- You are under 35 and have been trying to conceive for 12 months (or 6 months if 35+)
- Your period has stopped completely for 90 days or more (and you are not pregnant)
Frequently Asked Questions
Evidence-based answers to common questions about your cycle and fertility.
How many extra calories do you need during pregnancy?
Per ACOG and Dietary Guidelines for Americans: First trimester requires 0 additional calories above baseline; Second trimester requires approximately +340 kcal/day; Third trimester requires approximately +450 kcal/day.
Should I "eat for two" during pregnancy?
No. The concept of "eating for two" is a widespread myth. In reality, energy needs increase moderately (about an extra nutritious snack or small meal per day in trimesters 2 and 3). Focusing on nutrient density (folate, iron, calcium, protein) is far more important than doubling calorie intake.
Is it safe to diet or restrict calories while pregnant?
No. Caloric restriction or active weight loss during pregnancy is not medically recommended, as it can deprive the developing fetus of vital macronutrients and micronutrients necessary for organogenesis and brain development.
Pregnancy Weight Gain Calculator
Calculate healthy target weight gain ranges and weekly gain rates across each trimester based on your pre-pregnancy BMI and IOM guidance.
Due Date Calculator
Calculate your estimated baby due date, current gestational age, trimester, and weekly milestones from your LMP, conception, or ultrasound date.
Pregnancy Week Calculator
Calculate how many weeks and days pregnant you are today, identify your current trimester, and view baby developmental milestones.
Medical & Scientific Sources
- American College of Obstetricians and Gynecologists (ACOG)(2023). "Nutrition During Pregnancy"
- Mifflin MD, et al. (Am J Clin Nutr)(1990). "A new predictive equation for resting energy expenditure in healthy individuals"