Postpartum Calorie Needs Calculator Formula

Understand the math behind the postpartum calorie needs calculator. Each variable explained with a worked example.

Use the Postpartum Calorie Needs Calculator

Formulas Used

Maintenance Calories

maintenance_cal = bmr * activity_factor + nursing_extra

Gentle Weight Loss (-250)

gentle_loss = max(bmr * activity_factor + nursing_extra - 250, 1800)

BMR

bmr_display = bmr

Variables

VariableDescriptionDefault
weight_lbsCurrent Weight(lbs)155
height_inchesHeight(inches)65
ageAge(years)30
activity_factorActivity Level1.3
nursing_extraBreastfeeding?500
weight_kgDerived value= weight_lbs * 0.453592calculated
height_cmDerived value= height_inches * 2.54calculated
bmrDerived value= 10 * weight_kg + 6.25 * height_cm - 5 * age - 161calculated

How It Works

Postpartum Calorie Needs

This uses the Mifflin-St Jeor equation (female version) plus nursing calories.

Formula

BMR = 10 x Weight(kg) + 6.25 x Height(cm) - 5 x Age - 161

Maintenance = BMR x Activity Factor + Nursing Calories

A gentle deficit of 250 calories/day supports gradual weight loss of about 0.5 lbs per week. Never go below 1,800 kcal while breastfeeding.

Worked Example

A 30-year-old, 155 lb, 65-inch tall postpartum woman, lightly active, exclusively breastfeeding.

weight_lbs = 155height_inches = 65age = 30activity_factor = 1.3nursing_extra = 500
  1. 01Weight = 70.3 kg, Height = 165.1 cm
  2. 02BMR = 10(70.3) + 6.25(165.1) - 5(30) - 161 = 1,384
  3. 03Maintenance = 1,384 x 1.3 + 500 = 2,299 kcal
  4. 04Gentle loss = 2,299 - 250 = 2,049 kcal

Ready to run the numbers?

Open Postpartum Calorie Needs Calculator