How much breast milk does a newborn need per day?

Most newborns need about 19–30 oz (570–900 ml) of breast milk per day in the first month. A common rule of thumb is roughly 2.5 oz per pound of body weight per day. As they grow, daily intake often peaks around 25–35 oz/day by 1–3 months.

How much expressed milk should I put in each bottle?

Start with 2–3 oz (60–90 ml) per bottle for newborns. By 1–3 months, many babies take 3–5 oz (90–150 ml). At 4–6 months, 4–6 oz (120–180 ml) is common. Watch your baby's cues rather than forcing a set amount.

Can you overfeed a breastfed baby with a bottle?

Yes — bottles flow faster than the breast, so babies can take in more milk than they need before their brain registers fullness. Use a slow-flow nipple, pace the feeding, and watch for signs of fullness: turning away, slower sucking, or sealed lips.

Why does my baby drink more from the bottle than at the breast?

Bottles require less effort and milk flows continuously, while breastfeeding requires active sucking and has natural pauses. This is called 'flow preference' and is normal. Pace bottle feeding (hold bottle horizontal, pause every few minutes) to mimic breastfeeding.

How do I know if my baby is getting enough milk?

Key signs include: 6+ wet diapers per day after day 5, consistent weight gain, audible swallowing during feeds, and a content baby after most feeds. By 6 weeks, dirty diapers may decrease but wet diapers should remain frequent.

Do breastfed babies need more milk than formula-fed babies?

Breast milk is more easily digested, so breastfed babies may feed more frequently — but total daily volume is often similar or slightly less than formula. The calculator uses typical exclusive breast milk volumes. If you're combo feeding, the baby will need less breast milk.

Does my baby's weight affect how much milk they need?

Yes — heavier babies generally need more milk. The calculator uses weight as the primary input, with age as a modifier. Premature babies or those with specific medical needs may have different requirements and should follow their pediatrician's guidance.

How much milk will I need to pump for a day at work?

Estimate your baby's usual daily intake, then divide by the number of hours you'll be apart. Most working moms pump every 3–4 hours and bring home 1–1.5 oz per hour away from baby. The calculator shows a daily total you can use as a baseline.

Feeding Guide

Breast Milk Calculator: How Much Expressed Milk Should Baby Drink?

How much expressed breast milk does your baby need? Estimate daily and per-feeding amounts based on weight and age.

Educational use only — not medical advice

This calculator provides a general estimate. Every baby is different. Always follow your pediatrician's guidance, especially for premature infants or babies with feeding difficulties.

Your baby's details

Weight unit

Pounds (lb) Kilograms (kg)

Weight (lb)

Age (months)

Age (days)

Estimated daily breast milk need

20 oz

≈ 544 ml per day · 0–1 month

Per feeding: 1.7–2.5 oz (45–68 ml)8–12 feeds/day

Based on ~2.5 oz per lb per day, adjusted for age. Watch your baby's hunger and fullness cues.

How much breast milk does a baby need?

The amount of breast milk a baby needs depends primarily on their weight and age. A widely used rule of thumb is approximately 2.5 ounces of breast milk per pound of body weight per day. For metric users, that's roughly 150 ml per kilogram per day.

However, needs change as babies grow. Intake typically increases through the first 4–6 months, then gradually decreases as solids are introduced. Here are general daily ranges:

0–1 month: 19–30 oz (570–900 ml) per day — stomach is tiny but feeds are frequent.
1–3 months: 25–35 oz (750–1050 ml) per day — peak milk consumption for many babies.
4–6 months: 27–40 oz (800–1200 ml) per day — before solids begin, this is the highest volume phase.
6–9 months: 24–32 oz (720–960 ml) per day — solids start replacing some milk feeds.
9–12 months: 20–30 oz (600–900 ml) per day — milk remains important but is supplemented by food.
12+ months: 16–24 oz (480–720 ml) per day — toddler nursing or bottles alongside a varied diet.

Expressed milk feeding guide

Newborns (0–1 mo)

2–3 oz (60–90 ml) per feeding

Start small. Newborn stomachs hold only 1–2 oz at first. Offer 2 oz and increase if baby shows hunger cues after finishing.

1–3 months

3–5 oz (90–150 ml) per feeding

Baby's stomach has grown. Many take 3–4 oz per feeding. Watch for spit-up as a sign the bottle flow may be too fast.

4–6 months

4–6 oz (120–180 ml) per feeding

Largest per-feed volumes before solids. Some babies cluster feed in the evening and take smaller daytime bottles.

6–9 months

4–5 oz (120–150 ml) per feeding

Solids are introduced. Milk remains primary nutrition but volume per feed often drops slightly.

9–12 months

3–5 oz (90–150 ml) per feeding

Three meals plus snacks. Milk supplements a varied diet. Many babies drop to 4 nursing or bottle sessions.

12+ months

3–4 oz (90–120 ml) per feeding

Whole milk or continued breast milk alongside food. Offer in a cup rather than a bottle if possible.

Breast milk amount by age

These are average amounts for exclusively breast milk-fed babies. Combo-fed babies (breast milk + formula) will need proportionally less breast milk. Premature babies and those with special medical needs may require different volumes — always follow your pediatrician's advice.

Age	Daily total	Per feeding	Feeds/day
0–1 week	8–15 oz	0.5–1.5 oz	8–12
1–2 weeks	14–22 oz	1.5–2.5 oz	8–12
2–4 weeks	19–27 oz	2–3 oz	8–10
1–2 months	22–30 oz	2.5–4 oz	7–9
2–3 months	25–35 oz	3–5 oz	6–8
4–5 months	27–38 oz	4–6 oz	6–7
5–6 months	28–40 oz	4.5–6.5 oz	5–7
6–9 months	24–32 oz	4–5 oz	5–6
9–12 months	20–30 oz	3.5–5 oz	4–6
12+ months	16–24 oz	3–4 oz	3–4

Signs your baby is getting enough milk

Output and behavior are more reliable than counting ounces. Here's what to look for:

Wet diapers: 6+ per day after day 5 of life. Before that, 1 wet diaper per day of age (1 on day 1, 2 on day 2, etc.) is normal.
Dirty diapers: At least 3–4 bowel movements per day in the first month. After 6 weeks, some breastfed babies stool less frequently (even every few days) — this is normal if stools are soft.
Weight gain: Most babies regain birth weight by 10–14 days, then gain about 5–7 oz (150–200 g) per week for the first 3–4 months.
Swallowing sounds: You should hear audible swallowing during active feeding.
Content after feeds: Baby releases the breast or bottle on their own and appears relaxed or sleepy.
Steady growth on the curve: Your pediatrician will plot weight, length, and head circumference on growth charts.
Alert and active when awake: A well-fed baby is generally alert, responsive, and has good muscle tone.

Red flags to discuss with your pediatrician: Fewer than 6 wet diapers per day after day 5, no dirty diapers for 7+ days with discomfort, poor weight gain, persistent fussiness after most feeds, or signs of dehydration (dry mouth, sunken fontanelle, lethargy).

Quick Answer

Most babies need roughly 2.5 oz (75 ml) of breast milk per pound (per 0.45 kg) of body weight per day. Daily totals range from 19–30 oz for newborns up to 27–40 oz at 4–6 months, then gradually decrease as solids are introduced.

How it works

Daily oz = weight (lb) × 2.5 × age factor

The calculator uses a standard pediatric estimate of approximately 2.5 oz of breast milk per pound of body weight per day (or ~150 ml per kg).

An age factor adjusts this base amount: it increases slightly for 1–6 month olds (peak intake phase) and decreases after 6 months as solids supplement nutrition.

Per-feeding amounts are calculated by dividing the daily total by the typical number of feeds for that age group.