Breastfeeding Calorie Calculator (daily energy need, DRI 2023)

Understanding the breastfeeding calorie calculator — concept and principle

This calculator estimates daily energy needs while breastfeeding using the 2023 Dietary Reference Intakes for energy. It gives the need if not breastfeeding, the extra for breastfeeding, the energy in breast milk and the part usually covered by body fat in the first six months. Breastfeeding parents and dietitians use it for meal planning.

How it is calculated

• Need if not breastfeeding (women 19+) = constant − 7.01 × age + a × height (cm) + b × weight (kg)
• Constants by activity: inactive 584.90, 5.72, 11.71; low active 575.77, 6.60, 12.14; active 710.25, 6.54, 12.34; very active 511.83, 9.07, 12.56
• 0–6 months, exclusively breastfed: + 540 kcal for milk − 140 kcal from body fat = + 400
• 7–12 months with solids: + 380 kcal, no allowance for weight loss

The principle

Breastfeeding uses energy because the milk itself contains energy. The 2023 reference values from the US National Academies estimate about 540 kcal a day in milk during exclusive breastfeeding in the first six months. Part of that is usually met from fat stored in pregnancy, which is lost gradually after birth, so the net extra food energy is about 400 kcal. Later, when babies eat solids and drink less milk, the extra need is about 380 kcal with no allowance for weight loss.

Worked example

Defaults: 32 years, 162 cm, 62 kg, low active, baby 0–6 months.

1. Need if not breastfeeding = 575.77 − 7.01 × 32 + 6.60 × 162 + 12.14 × 62 = 575.77 − 224.32 + 1,069.20 + 752.68 = 2,173 kcal.
2. Energy in breast milk = 540 kcal; covered by body fat = 140 kcal.
3. Extra for breastfeeding = 400 kcal.
4. Daily need while breastfeeding = 2,173 + 400 = 2,573 kcal.

How to read the result

Use the figure as a starting point and let hunger, energy levels and weight trends guide you. Gradual weight loss in the months after birth is common; rapid loss or low milk supply are reasons to talk to a health professional. Food quality matters too: breastfeeding increases needs for some nutrients and fluids.

Common mistakes

• Adding the full 540 kcal in the first six months, ignoring fat stores.
• Choosing a higher activity level than real daily movement.
• Using pre-pregnancy weight instead of current weight.
• Strict dieting soon after birth.

Frequently asked questions

How many extra calories does breastfeeding need?

About 400 kcal a day in the first six months and about 380 kcal from 7 to 12 months, according to the 2023 DRIs.

Why subtract 140 kcal?

Part of the energy in milk usually comes from fat stored during pregnancy.

Does this apply to teenagers?

Under 19, different equations are used.

Sources: National Academies of Sciences, Engineering, and Medicine, Dietary Reference Intakes for Energy (2023), doi:10.17226/26818 · Health Canada, "Dietary reference intakes tables: Equations to estimate energy requirement"