Breastfeeding Calorie Needs Calculator

Work out breastfeeding calorie needs instantly with clear inputs, formula shown and shareable results.

About Breastfeeding Calorie Needs Calculator

Adds the lactation energy increment of about 500 kcal a day in the first six months, scaled by how much of the infant's intake is breast milk.

Formula

Lactation increments

+500 kcal/day for the first 6 months and +400 kcal/day from 7 to 12 months of exclusive breastfeeding; about 80% of that appears as milk energy

Worked example

With the default values below, Breastfeeding Calorie Needs Calculator returns Daily energy needs of 2,500. Change any input above and every figure here is recalculated in your browser.

Inputs used

Pre-pregnancy energy needsaccepts 1,200–4,000 kcal/day: 2,000 kcal/day
Stageone of First 6 months, 7 to 12 months: First 6 months
Share of feeding that is breast milkaccepts 20–100: 100

Results

Daily energy needs: 2,500 kcal/day
Additional energy for lactation: 500 kcal/day
Approximate energy secreted in milk: 400 kcal/day
Suggested total daily fluid: 3,000 mL

Step by step

1Values used
2Lactation increments
3Daily energy needs= 2,500 kcal/day
4Additional energy for lactation= 500 kcal/day
5Approximate energy secreted in milk= 400 kcal/day
6Suggested total daily fluid= 3,000 mL

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax or compounding frequency into account.
Figures are rounded for display to whole numbers, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.
This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.

Frequently Asked Questions

Does breastfeeding help weight loss?

It raises energy needs, so a modest deficit is usually easy, but very large deficits can reduce milk supply.

How much fluid is needed?

Around 3 litres a day in total including food, since milk output alone is about 750 mL.