Infant formula: common questions
How much formula does my baby need?
Newborn babies need quite small amounts of formula to start with. By the end of their first week, most will need around 150 to 200ml per kilo of their weight a day until they're 6 months old. This amount will vary from baby to baby.
Although most babies settle into a feeding pattern eventually, they vary in how often they want to feed and how much they want to drink.
Feed your baby when they show signs that they want it. Babies tend to feed little and often, so they may not finish their bottle. Having a big feed does not mean your baby will go longer between feeds.
The amount of formula may change if your baby is unwell, in pain due to teething, or having a growth spurt.
How do I know if my baby is getting enough formula?
Your baby's weight gain and the number of wet and dirty nappies will tell you whether your baby is getting enough formula.
Your baby should have around 6 wet nappies a day from a few days after the birth. Nappies should be soaked through with clear or pale yellow urine, or feel heavy.
For the first few days after birth, your baby will pass a dark, sticky substance known as meconium. After the first week your baby should start to pass pale yellow or yellowish brown poo.
Your baby will usually be weighed at birth and again at around 5 and 10 days. After that healthy babies only need to be weighed once a month up to 6 months of age.
This information should be entered on a chart in your Personal Child Health Record (PCHR) or "red book".
If you have any questions or concerns about your baby's weight gain, speak to a midwife or health visitor.
How will I know if my formula-fed baby is hungry?
After a while, you'll get to know the signs that show your baby is ready to feed:
- your baby will start to get restless
- they'll begin to turn their head and open their mouth (rooting)
- they'll find something to suck – usually their fist or fingers
Try to feed your baby before they cry, as this is a late sign of hunger.
What do I need if I'm formula feeding away from home?
If you need to feed your baby away from home, take with you:
- a measured amount of formula powder in a small, clean and dry container
- a vacuum flask of hot water that's just been boiled
- an empty sterilised feeding bottle with cap and retaining ring in place
The vacuum flask does not need to be sterilised, but should be clean, and only used for your baby. The boiling water should kill any bacteria present in the flask. If the flask is full and sealed, the water will stay above 70C for several hours.
Make up a fresh feed only when your baby needs it. The water must still be hot when you use it, to destroy any bacteria in the formula powder.
Remember to cool the bottle (with the lid on) under cold running water before you feed it to your baby.
Alternatively, you could use a carton of ready-to-feed liquid formula when you're away from home.
What if I need to transport a made-up feed?
If it is not possible to follow the advice above, or if you need to transport a feed (for example, to a nursery), prepare the feed at home, cool under a running tap or in a bowl of cold water, and cool it for at least 1 hour in the back of the fridge.
Take it out of the fridge just before you leave and carry it in a cool bag with an ice pack, and use it within 4 hours. If you do not have an ice pack, or access to a fridge, the made-up infant formula must be used within 2 hours.
If made-up formula is stored:
- in a fridge – use within 24 hours
- in a cool bag with an ice pack – use within 4 hours
- at room temperature – use within 2 hours
Can I use bottled water to make up infant formula?
Bottled water is not recommended for making up infant formula feeds for your baby. This is because it's not usually sterile and may contain too much salt (sodium) or sulphate.