Find your daily calorie needs during pregnancy — your pre-pregnancy TDEE plus the extra energy each trimester requires.
Pregnancy calorie needs are calculated by starting with your pre-pregnancy TDEE (Total Daily Energy Expenditure) and adding the extra energy your body needs to support fetal growth, placental development, and increased maternal blood volume. This calculator uses the Mifflin-St Jeor equation for your baseline TDEE, then applies the trimester-specific additions used in ACOG and Institute of Medicine guidance.
| Trimester | Weeks | Extra Calories/Day |
|---|---|---|
| 1st Trimester | 1–13 | +0 (no extra calories generally needed) |
| 2nd Trimester | 14–27 | +340 calories |
| 3rd Trimester | 28–40 | +450 calories |
Many people assume pregnancy means "eating for two" from day one — in reality, most of the extra energy need doesn't appear until the second trimester, and even then it's a few hundred calories, not double your normal intake.
Once your baby arrives, our Breastfeeding Calorie Calculator covers the next phase of postpartum energy needs.
Breastfeeding has its own calorie requirements, separate from pregnancy.
See Breastfeeding Calorie Needs →Generally no. Most guidelines recommend no additional calories in the first trimester — fetal energy demands are still very low. Focus on nutrient quality (folate, iron, protein) rather than quantity during this stage.
Around 450 extra calories per day above your pre-pregnancy TDEE, reflecting the highest rate of fetal growth in the final trimester.
Not really. Even in the third trimester, the extra calorie need is roughly 450 calories — around 15-20% more than baseline, not double. "Eating for two" often leads to excess weight gain beyond recommended ranges.
This calculator is built for a single pregnancy. Multiples typically require additional calories beyond the standard trimester figures — talk to your OB-GYN or a registered dietitian for personalized targets.