Breastfeeding Calorie Calculator

This breastfeeding calorie calculator estimates how many calories you need each day while you are nursing, combining your maintenance energy needs with the extra your body uses to make milk. Enter your age, weight, height, activity level and how much you are breastfeeding, and the calculator estimates your maintenance calories using the Mifflin-St Jeor equation and an activity factor, then adds a breastfeeding allowance on top. Producing breast milk is energy-hungry, and health guidance in New Zealand and internationally suggests exclusively breastfeeding mothers need roughly 500 extra calories a day in the first six months, with less required once solids are introduced or if you are combination feeding. Some of that energy is drawn from the fat stores laid down in pregnancy, which is why gradual weight loss while breastfeeding is normal and expected. This tool gives you a realistic daily target so you can eat enough to support your supply and your own recovery, rather than under-eating during a demanding time. It is an estimate only: real needs vary with your baby's age, how often you feed, whether you pump, and your own metabolism. Use it as a starting point, listen to your hunger, and talk to your midwife, Plunket nurse or a dietitian before cutting calories to lose weight.

Calculate.co.nz is proud to be partnered with Premium Homes, a recognised leader in eco-friendly, sustainable, and energy-efficient homebuilding. With a dedicated team and award-winning experience, they create homes that prioritise health, comfort, and long-term performance. Their founders, Andrew and Kelly, set out to raise the standard of residential construction in New Zealand by combining practical building expertise with a clear commitment to doing things better for homeowners.
Premium Homes: got a section? Let's build your eco home on it.
Advertise on this page
years
kg
cm
2,425 kcal
suggested daily calories while breastfeeding
Maintenance (BMR)1,400 kcal
Maintenance (with activity)1,925 kcal
Breastfeeding allowance+500 kcal

At 68 kg and 165 cm, age 30, your estimated maintenance is about 1,925 kcal a day. Exclusive breastfeeding adds roughly 500 kcal, for about 2,425 kcal daily while you are nursing.

Estimate only, not medical or dietary advice. Needs vary with your baby's age and feeding pattern. Talk to your midwife, Plunket nurse or a dietitian before restricting calories.

How it works

Your basal metabolic rate, the energy your body uses at rest, is estimated with the Mifflin-St Jeor equation for women: 10 times weight in kilograms, plus 6.25 times height in centimetres, minus 5 times age, minus 161. Multiplying by an activity factor gives your maintenance calories, the amount that keeps your weight steady. On top of that, a breastfeeding allowance is added: about 500 calories for exclusive feeding, less for partial or occasional feeding, reflecting the energy cost of making milk. The total is a realistic daily target while you are nursing.

Worked example

Take a 30 year old who is 165 cm and 68 kg and lightly active, feeding exclusively. Her BMR is 10 x 68 + 6.25 x 165 - 5 x 30 - 161 = 1,400 calories. With a light-activity factor of 1.375, maintenance is about 1,925 calories a day. Exclusive breastfeeding adds roughly 500 calories, giving a suggested 2,425 calories daily. If she moved to partial feeding, the allowance would drop to about 300 calories and the target to around 2,225.

Related calculators