Breastfeeding calorie calculator

Estimate how many calories a day you need while breastfeeding: your usual maintenance calories plus the extra that US guidelines give for making milk.

By the Calcist team · Checked against known answers · Updated October 27, 2026

Private: calculated on your device. Nothing you type is sent anywhere.

A general estimate from a published formula, not medical advice.

Next: Want to see your daily needs at every activity level? Try the TDEE calculator. For protein, see the protein calculator.

What this calculator does

Making breast milk uses energy, so calorie needs go up while you breastfeed. This calculator estimates your usual (non-pregnant) maintenance calories, then adds the extra that US guidelines give for lactation. It shows both the Dietary Guidelines for Americans figure and the newer 2023 National Academies figure, so you can see how close they are.

How it's calculated

BMR (Mifflin–St Jeor, women) = 10 × kg + 6.25 × cm − 5 × age − 161
Maintenance = BMR × activity factor
Daily calories = maintenance + extra for breastfeeding

Baby's age	Dietary Guidelines 2020–2025	National Academies DRI 2023
0–6 months	+330 kcal	+400 kcal (540 for milk − 140 from body stores)
7–12 months	+400 kcal	+380 kcal

The Dietary Guidelines figures are for people who had a healthy weight before pregnancy. The 2023 DRI values assume exclusive breastfeeding for the first 6 months, partial breastfeeding from 7 to 12 months, and a gradual weight loss of about 0.64 kg (1.4 lb) a month in the first 6 months. The activity factors are the same ones the TDEE calculator uses.

Worked example

A 30-year-old, 5 ft 5 in (165.1 cm), 150 lb (68.04 kg), lightly active, with a 3-month-old:

BMR = 680.4 + 1,031.9 − 150 − 161 = 1,401 kcal
Maintenance = 1,401 × 1.375 = 1,927 kcal
Breastfeeding, 0–6 months: 1,927 + 330 = 2,257 kcal a day

With the 2023 DRI figure it would be 1,927 + 400 = 2,327 kcal.

Fluids

The National Academies set an Adequate Intake for total water of 3.8 liters a day during lactation, compared with 2.7 liters for other women aged 19 to 50. Total water counts all water from drinks and food, so it isn't the same as glasses of water.

Limitations

This is an estimate. Real needs vary with your body, activity, how much milk you make, and whether you also use formula. The CDC notes that the extra amount varies with age, BMI, activity and how exclusively you breastfeed.
If you also use formula, your extra need may differ from the table. The DRI's 7–12 month figure is for partial breastfeeding.
Twins, a low milk supply, a medical condition, or concerns about weight or your baby's growth are good reasons to talk to your doctor, a registered dietitian or a lactation consultant.
It's not for people under 18, whose needs include their own growth.

Sources

ODPHP (health.gov): Nutrition During Breastfeeding: How Health Professionals Can Support Healthy Moms and Babies — the Dietary Guidelines for Americans 2020–2025 figures of about 330 and 400 extra calories.
National Academies of Sciences, Engineering, and Medicine. Dietary Reference Intakes for Energy (2023), Summary, Tables S-5 and S-6 — milk production 540 kcal/d minus 140 kcal/d mobilized (0–6 months) and 380 kcal/d (7–12 months).
CDC: Maternal Diet and Breastfeeding
National Academies DRI tables: Total Water and Macronutrients — total water Adequate Intake of 3.8 L a day during lactation and 2.7 L for other women 19–50.
Mifflin MD, St Jeor ST, et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr 1990;51:241–247.

How we checked this

Before every update, this calculator is run in a real browser with these known answers, and it must match all of them:

30, 5 ft 5 in, 150 lb, lightly active, 0–6 months (DGA +330): 2,257 kcal ✓
Same mother, maintenance before the extra: 1,927 kcal ✓
Same mother, 7–12 months (DGA +400): 2,327 kcal ✓
Same mother, 7–12 months with the 2023 DRI (+380): 2,307 kcal ✓
28, 165 cm, 65 kg, sedentary, 0–6 months, 2023 DRI (540 − 140 = +400): 2,056 kcal ✓
Age 17: adult formula not used ✓

Last checked October 26, 2026. Spotted something wrong? The math is done in your browser with the formula shown on this page, so you can check any result by hand.

Add this calculator to your website (free)

Paste this code into any web page. The calculator works on your page, resizes itself, has no ads and no tracking, and nothing your visitors type is sent anywhere. More about embedding.

<iframe src="https://calcist.com/embed/breastfeeding-calorie-calculator/" title="Breastfeeding calorie calculator" width="100%" height="640" loading="lazy" style="border:0;max-width:760px"></iframe>
<p style="font:14px/1.4 sans-serif;margin:4px 0 0"><a href="https://calcist.com/breastfeeding-calorie-calculator/">Breastfeeding calorie calculator</a> by Calcist</p>
<script src="https://calcist.com/embed.js" async></script>

Questions people ask

How many extra calories do you need when breastfeeding?

The Dietary Guidelines for Americans 2020–2025 say about 330 extra calories a day in the first 6 months and 400 in the second 6 months, for people with a healthy weight before pregnancy. The CDC gives 330 to 400.

How many calories does breastfeeding burn?

The 2023 National Academies report estimates the energy cost of milk at about 540 kcal a day when exclusively breastfeeding for 0–6 months, and 380 kcal a day at 7–12 months. Part of the early cost is met from fat stored during pregnancy.

Can I diet while breastfeeding?

The 2023 DRI figure already assumes a gradual loss of about 0.64 kg (1.4 lb) a month in the first 6 months. Talk to your doctor or a registered dietitian before cutting calories further.

How much water should I drink while breastfeeding?

The Adequate Intake for total water during lactation is 3.8 liters a day, counting water from drinks and food. That compares with 2.7 liters for other women aged 19 to 50.

Is the extra 330 calories right for everyone?

No. The Dietary Guidelines figure is for people with a healthy weight before pregnancy, and health professionals are advised to tailor it, for example to pre-pregnancy weight and weight gained during pregnancy.

Related calculators

TDEE calculatorTotal daily energy expenditure at every activity level.Calorie calculatorDaily calories to maintain, lose or gain weight at a steady rate.Protein calculatorDaily protein from the RDA and sports nutrition ranges.BMR calculatorCalories burned at rest: Mifflin–St Jeor, Harris–Benedict, Katch–McArdle.Due date calculatorEstimated due date from your last period, conception, IVF transfer or ultrasound.