Breastfeeding adds about 330 kcal a day in the first six months and about 400 kcal a day from seven to twelve months on top of your normal TDEE, according to the Dietary Reference Intakes. A 32-year-old woman, 5′5″ and 165 lb, who is moderately active has a TDEE of 2,262 kcal, so she needs about 2,592 kcal in months 0–6. This is not medical advice.
Key takeaways
- The Dietary Reference Intakes add about 330 kcal a day for months 0–6 of breastfeeding and about 400 kcal a day for months 7–12.
- The example 32-year-old woman (165 lb, 5′5″, moderately active) has a TDEE of 2,262 kcal and needs about 2,592 kcal (months 0–6) or 2,662 kcal (months 7–12).
- If you want to lose weight, a small deficit of around 250 kcal below your breastfeeding total is a gentle starting point, not an aggressive cut.
- Lactation guidance commonly advises not going below about 1,800 kcal a day while breastfeeding unless a doctor or lactation consultant is supervising, and checking in with them if milk supply changes.
How this breastfeeding calorie calculator works
Enter your age, weight, height and activity level, then use the pregnancy and breastfeeding selector to choose “Breastfeeding, 0–6 months” or “Breastfeeding, 7–12 months”. The calculator estimates your TDEE with Mifflin–St Jeor (Mifflin et al., 1990) and adds the extra calories for that stage. It starts on the maintain goal.
This page covers calorie math only. It is not medical advice, and it is not a substitute for care from your doctor, midwife or lactation consultant.
How many extra calories does breastfeeding need?
The Dietary Reference Intakes add 330 kcal a day during the first six months of lactation and 400 kcal a day during the second six months (Institute of Medicine, 2005).
| Stage | Extra calories | Example woman’s total |
|---|---|---|
| Not breastfeeding | 0 | 2,262 kcal |
| Breastfeeding, 0–6 months | +330 | 2,592 kcal |
| Breastfeeding, 7–12 months | +400 | 2,662 kcal |
Your activity level should reflect your actual routine with a baby. For many new mothers that is lower than before birth, so pick the level that honestly matches your week, and treat the result as a starting point.
Can I lose weight while breastfeeding?
Some women do, but slowly. Large deficits are hard to sustain and to fuel well, particularly when you are also producing milk and not sleeping much. A small deficit is a gentler plan than a standard diet.
A practical starting point is a deficit of about 250 kcal a day below your breastfeeding total, which is roughly 0.5 lb (0.23 kg) a week at first:
| Stage | Maintenance total | With a 250 kcal deficit |
|---|---|---|
| Months 0–6 | 2,592 kcal | 2,342 kcal |
| Months 7–12 | 2,662 kcal | 2,412 kcal |
These are hand-calculated from the numbers above. They are well above the commonly advised floor of about 1,800 kcal while breastfeeding, and the deficit is far smaller than the 10–20% paces used for non-lactating adults. Be cautious about going further, and check any plan with your doctor or a lactation consultant. If you are not breastfeeding, use the calorie deficit calculator instead.
What if my milk supply drops?
If you notice your baby feeding differently, fewer wet nappies, or a drop in supply, stop dieting, eat more and contact a lactation consultant or your doctor promptly. Calculators cannot see supply, so symptoms always override the number.
What else should I know about eating while breastfeeding?
- Protein and balance: keep protein adequate with regular meals. The protein calculator gives ranges for general adults, and your clinician can tailor them.
- Do not skip meals to create a deficit; consistent, nutritious eating supports energy.
- Check your intake against the floors: lactation guidance commonly advises not going below about 1,800 kcal a day unless a doctor or lactation consultant is supervising, and check in with them if milk supply changes.
- See a professional first if you have a history of disordered eating, take medication, or are under 18.
For general maintenance numbers outside of breastfeeding, see the TDEE calculator for women and the maintenance calories calculator.
Does the calculator change my goal for breastfeeding?
The tool starts on the maintain goal, because maintaining is the usual default in the early months. If you switch to a lose goal, the pace options (10%, 15% or 20% below) are the same as for any adult, so check the result against the gentle approach above and your clinician’s advice before using it. The 250 kcal deficit in the table is a more conservative choice than the app’s presets, and you can work it out by hand from your maintenance total.
Frequently asked questions
How many calories do you burn breastfeeding?
Guidelines estimate that milk production needs roughly 330 kcal a day in months 0–6 and 400 kcal a day in months 7–12 above your usual needs. The figures are population averages, and actual needs vary with how much milk you produce and how much of your baby's intake is breast milk.
How many calories should I eat while breastfeeding to lose weight?
Start from your TDEE plus the lactation allowance, then take off a small amount, such as 250 kcal. For the example woman that is about 2,342 kcal in months 0–6. Keep losses slow and speak with your doctor or a lactation consultant first.
Can dieting reduce my milk supply?
Large deficits might, and this page cannot say how much or for whom. If you notice a drop in supply, eat more, slow down and contact a lactation consultant or your doctor. Avoid very low intakes while breastfeeding.
When can I start trying to lose weight after having a baby?
That is a medical question. Ask your obstetrician, midwife or doctor, who can consider your delivery, your health and how your baby is feeding.
Does the breastfeeding allowance replace my deficit?
No, it raises your maintenance. Your TDEE plus 330 or 400 kcal is the amount that keeps weight steady. Any deficit is subtracted from that total. The calorie deficit calculator shows how paces compare, although it does not add the breastfeeding allowance.
References
- Institute of Medicine (2005). Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. The National Academies Press.
- Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO (1990). A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition 51(2):241–247.