acalculator

How many breastfeeding calories?

Type your age, height, weight and activity level, and choose your baby’s age. The breastfeeding calorie calculator adds the energy cost of making milk to your usual energy needs, with the 2023 National Academies equations. It is a planning estimate, not a diet prescription.

Your numbers

Units
Baby’s age
Calories a day
2,664

You need about 2,664 calories a day while breastfeeding.

Without breastfeeding
2,264
Extra for breastfeeding
400
Energy in milk production
540

Calories a day: 2,664. You need about 2,664 calories a day while breastfeeding.

This calculator gives general information only. It is not medical advice and does not replace a doctor or other health care provider. Talk with a professional about your results. Terms of use

How to calculate

Estimates the daily calories a breastfeeding mother needs: the 2023 National Academies energy requirement for her age, height, weight and activity, plus 400 kcal a day for 0 to 6 months or 380 kcal for 7 to 12 months.

Example with the default inputs (Age 30, Height 5 ft 4 in, Weight 150 lb, Physical activity Low active, Baby’s age 0 to 6 months): You need about 2,664 calories a day while breastfeeding.

Method: Total = EER + lactation cost; EER (women 19+) = constant − 7.01 × age + h × height (cm) + w × weight (kg) by activity level; lactation 0 to 6 months = 540 − 140 = 400 kcal/d, 7 to 12 months = 380 kcal/d.

  • Women aged 19 and older; teenagers use the girls’ equations.
  • 0 to 6 months assumes exclusive breastfeeding and a weight loss of about 0.64 kg a month; 7 to 12 months assumes partial breastfeeding and a stable weight.
  • An average for planning; appetite, weight change and your care team’s advice come first.

Machine-readable copies: Markdown, JSON.

Worked examples

Each example is checked against the calculator on every build.

  1. Age 30, Height 5 ft 5 in, Weight 149.9 lb, Physical activity Low active, Baby’s age 0 to 6 months gives Without breastfeeding 2,279.99, Calories a day 2,679.99, Extra for breastfeeding 400.Source: National Academies of Sciences, Engineering, and Medicine, Dietary Reference Intakes for Energy (2023), Summary, Tables S-1 (EER for women 19 and older) and S-5, S-6 (lactation: 0 to 6 months + 540 − 140 kcal/d; 7 to 12 months + 380 kcal/d), https://www.nationalacademies.org/read/26818/chapter/2 (retrieved 2026-10-05)
  2. Age 35, Height 5 ft 4 in, Weight 150 lb, Physical activity Inactive, Baby’s age 7 to 12 months gives Without breastfeeding 2,066.128198, Extra for breastfeeding 380, Energy in milk production 380.Source: National Academies of Sciences, Engineering, and Medicine, Dietary Reference Intakes for Energy (2023), Summary, Tables S-1 (EER for women 19 and older) and S-5, S-6 (lactation: 0 to 6 months + 540 − 140 kcal/d; 7 to 12 months + 380 kcal/d), https://www.nationalacademies.org/read/26818/chapter/2 (retrieved 2026-10-05)
  3. Age 25, Height 5 ft 6.9 in, Weight 132.3 lb, Physical activity Very active, Baby’s age 0 to 6 months gives Without breastfeeding 2,632.08, Calories a day 3,032.08.Source: National Academies of Sciences, Engineering, and Medicine, Dietary Reference Intakes for Energy (2023), Summary, Tables S-1 (EER for women 19 and older) and S-5, S-6 (lactation: 0 to 6 months + 540 − 140 kcal/d; 7 to 12 months + 380 kcal/d), https://www.nationalacademies.org/read/26818/chapter/2 (retrieved 2026-10-05)
  4. Age 30, Height 5 ft 5 in, Weight 149.9 lb, Physical activity Active, Baby’s age 0 to 6 months gives Without breastfeeding 2,418.17, Calories a day 2,818.17.Source: National Academies of Sciences, Engineering, and Medicine, Dietary Reference Intakes for Energy (2023), Summary, Tables S-1 (EER for women 19 and older) and S-5, S-6 (lactation: 0 to 6 months + 540 − 140 kcal/d; 7 to 12 months + 380 kcal/d), https://www.nationalacademies.org/read/26818/chapter/2 (retrieved 2026-10-05)

How it works

Estimated energy requirement (EER) for women 19 and older (National Academies 2023, Table S-1), age in years, height in cm, weight in kg, in kcal a day:

ActivityEER
Inactive584.90 − 7.01 × age + 5.72 × height + 11.71 × weight
Low active575.77 − 7.01 × age + 6.60 × height + 12.14 × weight
Active710.25 − 7.01 × age + 6.54 × height + 12.34 × weight
Very active511.83 − 7.01 × age + 9.07 × height + 12.56 × weight

Lactation cost (Tables S-5 and S-6):

  • Baby 0 to 6 months (exclusive breastfeeding): milk production 540 kcal a day − 140 kcal a day from body stores = +400 kcal a day.

  • Baby 7 to 12 months (partial breastfeeding): milk production +380 kcal a day, nothing from body stores.

  • Calories a day = EER + lactation cost. Without breastfeeding = EER. Extra for breastfeeding = 400 or 380. Energy in milk production = 540 or 380.

Rules. Age 19 to 60; height 120 to 210 cm; weight 35 to 250 kg.

Exact arithmetic and output format. Height and weight are read as the exact decimals typed, in their units (5 ft 4 in is exactly 162.56 cm; 150 lb is exactly 68.0388555 kg). Results are exact and rounded once, half up, to whole kilocalories.

Assumptions

  • Women 19 and older; the equations for girls 14 to 18 differ.
  • 0 to 6 months assumes a gradual weight loss of 0.64 kg a month.

Worked examples by hand

30, 165 cm, 68 kg, low active, baby 0 to 6 months. EER = 575.77 − 7.01 × 30 + 6.60 × 165 + 12.14 × 68 = 575.77 − 210.30 + 1,089.00 + 825.52 = 2,279.99 (shown 2,280). Total = 2,279.99 + 400 = 2,679.99 (shown 2,680).

35, 5 ft 4 in, 150 lb, inactive, baby 7 to 12 months. Height 162.56 cm; weight 68.0388555 kg. EER = 584.90 − 245.35 + 5.72 × 162.56 + 11.71 × 68.0388555 = 584.90 − 245.35 + 929.8432 + 796.7350 = 2,066.13 (shown 2,066). Total = 2,446.13 (shown 2,446).

30, 165 cm, 68 kg, active, baby 0 to 6 months. EER = 710.25 − 210.30 + 6.54 × 165 + 12.34 × 68 = 710.25 − 210.30 + 1,079.10 + 839.12 = 2,418.17. Total = 2,818.17 (shown 2,818).

25, 170 cm, 60 kg, very active, baby 0 to 6 months. EER = 511.83 − 175.25 + 1,541.90 + 753.60 = 2,632.08. Total = 3,032.08 (shown 3,032).

Other questions people ask

How many extra calories do I need while breastfeeding?

The 2023 National Academies values add about 400 kcal a day in the first 6 months (540 kcal for making milk, less 140 kcal that comes from body stores) and 380 kcal a day from 7 to 12 months. The CDC recommends an extra 330 to 400 kcal a day for well-nourished breastfeeding mothers.

How is my total calculated?

First your estimated energy requirement (EER) from the 2023 equation for women 19 and older at your activity level, using age, height in cm and weight in kg. Then the lactation cost for your baby’s age is added.

Why is the extra lower than the energy in the milk in the first 6 months?

Part of the energy for milk comes from fat stored during pregnancy. The equations assume a gradual weight loss of about 0.64 kg (1.4 lb) a month in the first 6 months, which supplies about 140 kcal a day.

Can I diet to lose weight while breastfeeding?

The 0 to 6 months values already assume a gradual loss of 0.64 kg (1.4 lb) a month. Talk with your doctor or a lactation consultant before eating less than that.

Does pumping count as breastfeeding here?

Yes. The cost is for making milk, so exclusive pumping counts the same as nursing. Use the 0 to 6 months option when breast milk is all or nearly all of what your baby drinks.

Do I need more water while breastfeeding?

Yes. Breastfeeding raises the Adequate Intake for water. The water intake calculator gives the Adequate Intake for lactation.