"Is she getting enough?", "Should I wake him for a feed?", "Why is she suddenly hungrier than yesterday?": milk amounts are one of the biggest worries for new parents. The good news: there's no single number, just guidelines, and one simple principle: listen to your baby.
How much milk does a baby need? The "on-demand" principle
Before any number, remember this: a healthy baby regulates their own appetite. Current guidance is to feed on demand, in response to hunger cues, rather than following a chart to the letter.
So the amounts below are averages for reassurance, not targets to hit at all costs. On a growth-spurt day your baby will take more; on another, less. That's normal.
A simple rule to estimate daily needs
For formula-fed babies, a widely used rule of thumb (NHS) is:
About 150-200 ml of formula per kilogram of body weight per day, until around 6 months, split across feeds.
For example, a 1-month-old weighing about 4 kg might need roughly 600-800 ml a day. Divide that total by the number of feeds to get an amount per bottle, then adjust to your baby's real appetite.
Formula amounts by age (guide)
| Age | Per feeding | Feedings per day |
|---|---|---|
| 0-1 week | 1-3 oz (30-90 ml) | 6 to 8 |
| 2-4 weeks | 3-4 oz (90-120 ml) | 6 to 7 |
| 1-2 months | 4-5 oz (120-150 ml) | 5 to 6 |
| 3-4 months | 5-6 oz (150-180 ml) | 5 |
| 5-6 months | 6-8 oz (180-240 ml) | 4 to 5 |
| After solids start | keep offering plenty of milk daily | , |
These figures are for information only and don't replace your pediatrician's advice. If you have any concern about your baby's growth, weight or appetite, get it checked.
Breastfeeding: no millilitres to count
At the breast, you don't measure millilitres. Regulation happens naturally: your baby feeds to appetite, and milk supply adjusts to demand. The useful markers are the number of feeds (8 to 12 per 24h for a newborn), wet nappies, and the weight curve tracked by your health professional.
Spotting hunger and fullness
Rather than a number, trust your baby's signals.
- Hunger cues: stirring, turning the head and rooting, bringing hands to the mouth, sucking sounds. Crying is a late cue.
- Fullness cues: slowing down, turning away, closing the mouth, relaxing or falling asleep. No need to push to "finish" the bottle.
Track bottles and feeds without the mental load
Counting bottles, remembering the last feed, noticing your baby has been drinking less for two days… that's exactly the kind of detail that overloads a new parent's brain.
Ambrette logs every bottle (amount) and every breastfeed (side, duration) in two taps, computes daily totals and shares everything with your co-parent, grandparents or nanny. You can spot a drop in appetite to flag to your pediatrician at a glance, and your data is never sold.
To go further, read our guides Tracking breastfeeding: side, duration, frequency, How many diapers per day by age and Starting solids: where to begin?.
Frequently asked questions
How much formula for a 1-month-old?
Around 1 month, a formula-fed baby takes about 4 to 5 oz (120-150 ml) per feeding, 5 to 6 times a day. These are averages: appetite varies from baby to baby, so follow hunger and fullness cues rather than a fixed number.
How do I work out how much formula my baby needs?
A common rule is about 150-200 ml of formula per kilogram of body weight per day, until around 6 months, split across feeds. For a 4 kg baby that's roughly 600-800 ml a day. It's an estimate, not a target to force.
Should I make my baby finish the bottle?
No. Babies regulate their own appetite, and forcing can disrupt that. If they turn their head away, close their mouth or fall asleep content, they've had enough. If they still seem hungry, you can offer a little more.
Sources
- Centers for Disease Control and Prevention (CDC), How Much and How Often to Feed Infant Formula.
- American Academy of Pediatrics (HealthyChildren.org), Amount and Schedule of Baby Formula Feedings.
- World Health Organization (WHO), Infant and young child feeding.
