Breastfeeding Calorie Calculator

Calorie Needs During Pregnancy and Breastfeeding

Daily energy needs rise during pregnancy and lactation to support fetal growth, milk production, and maternal health. This calculator uses the Mifflin-St Jeor equation for basal metabolic rate (BMR), multiplies by activity level, then adds trimester-specific pregnancy extras or lactation bonuses from Dietary Guidelines for Americans. Compare with the TDEE Calculator, Pregnancy Weight Gain Calculator, and BMR Calculator.

Mifflin-St Jeor BMR

For women, BMR in kcal/day is:

$$BMR = 10 \times weight_{kg} + 6.25 \times height_{cm} - 5 \times age - 161$$

Daily maintenance calories equal BMR multiplied by an activity factor (1.2 for sedentary up to about 2.0 for athletes).

Pregnancy and Lactation Extras

• First trimester: no additional calories beyond maintenance
• Second trimester: about +340 kcal/day
• Third trimester: about +452 kcal/day
• Lactation 0 to 6 months: +330 kcal/day
• Lactation after 6 months: +400 kcal/day