Pregnancy Calorie Calculator
Calculates your total daily calorie needs during pregnancy by combining your basal metabolic rate, activity level, and trimester-specific energy additions. Essential for healthy gestational weight gain.
About this calculator
This calculator uses the Mifflin–St Jeor equation for women to estimate Basal Metabolic Rate (BMR): BMR = 447.593 + (9.247 × weight_kg) + (3.098 × height_cm) − (4.330 × age). Weight in pounds is converted to kg (÷ 2.205) and height in inches to cm (× 2.54). BMR is then multiplied by an activity factor to get Total Daily Energy Expenditure (TDEE). Finally, a trimester bonus is added: +0 kcal in the first trimester, +340 kcal in the second, and +450 kcal in the third, in line with Institute of Medicine recommendations. The final result is: Daily Calories = TDEE + trimesterBonus. This accounts for the growing fetus, placenta, and increased maternal tissue demands at each stage.
How to use
Say you are 28 years old, weigh 140 lbs (63.5 kg), stand 65 inches tall (165.1 cm), are in your second trimester, and are lightly active (activity factor 1.375). BMR = 447.593 + (9.247 × 63.5) + (3.098 × 165.1) − (4.330 × 28) = 447.6 + 587.2 + 511.5 − 121.2 = 1,425 kcal. TDEE = 1,425 × 1.375 = 1,959 kcal. Add the second-trimester bonus: 1,959 + 340 = 2,299 kcal per day. This is your estimated daily target for healthy weight gain during the second trimester.
Frequently asked questions
How many extra calories do you need per day during pregnancy by trimester?
The Institute of Medicine recommends no additional calories in the first trimester, approximately 340 extra calories per day in the second trimester, and approximately 450 extra calories per day in the third trimester. These additions fuel placental growth, increased blood volume, and fetal fat and brain development. Individual needs vary based on pre-pregnancy BMI and activity level, so these are averages. Women carrying multiples require additional calories beyond these standard increments.
What activity level should I choose in the pregnancy calorie calculator?
Activity levels correspond to standard multipliers: sedentary (desk job, little exercise) uses 1.2; lightly active (light exercise 1–3 days/week) uses 1.375; moderately active (exercise 3–5 days/week) uses 1.55; and very active (hard exercise most days) uses 1.725. During pregnancy, many women reduce intensity in the third trimester, so you may need to re-run the calculation each trimester. Your healthcare provider can help confirm the appropriate level, especially if you have a high-risk pregnancy.
Should I restrict calories during pregnancy if I am overweight?
Caloric restriction is generally not recommended during pregnancy, even for overweight women, as it can limit fetal nutrient supply. However, the recommended gestational weight gain is lower for overweight (BMI 25–29.9: 15–25 lbs) and obese women (BMI ≥30: 11–20 lbs) than for normal-weight women. Rather than cutting calories, focus on nutrient-dense foods and appropriate activity. Always consult your OB or a registered dietitian before adjusting caloric intake during pregnancy.