Overview
Enough bottles for the feeds between washes, plus one spare. For a newborn on bottles only, washed twice a day, that’s about 5 to 7. If you mostly breastfeed and give the odd bottle, 2 is plenty.
Nobody publishes an official number. Every bottle has to be cleaned after each feed, [1] so how often you wash matters as much as how often your baby eats.
Count feeds Most formula-fed newborns feed 8 to 12 times in 24 hours. Over the first weeks and months, that spaces out to about every 3 to 4 hours. [2]
Count washes Take the day’s bottle feeds, divide by the number of times you wash, then add one spare.
Size A 5 oz (160 ml) bottle covers the early months for most babies. The 8 oz (240 ml) earns its place once feeds reach 6 to 8 oz, around 6 months for many formula-fed babies. [3]
A starting count by feeding style
These counts assume you wash twice a day. More washes, fewer bottles.
| How you feed | Bottle feeds a day | Bottles to start with |
|---|---|---|
| Formula or pumped milk only, first weeks | 8 to 12 [2] | 5 to 7 |
| Formula or pumped milk only, once feeds are every 3 to 4 hours | About 6 to 8 [2] | 4 to 5 |
| Combination feeding | Count only the bottle feeds | Bottle feeds between washes, plus 1 |
| Mostly breastfeeding, with an occasional bottle | 0 to 2 | 2 |
| Daycare days | The bottle feeds while you’re apart | That number plus 1 for daycare, on top of your set at home |
How to work out your own number
- Count the bottle feeds in a day. Use your baby’s real pattern. For a newborn, 8 to 12 in 24 hours is a fair start.
- Decide when you’ll wash. Once a day, twice, or after every feed.
- Divide and round up. Bottle feeds a day, divided by washes a day.
- Add one spare. For the bottle that rolled under the car seat, or the night you’re too tired to wash anything.
Say your 3-week-old is on formula and feeds about 8 times a day. You wash morning and evening. That’s about 4 feeds between washes, so 5 bottles with the spare.
Making up formula ahead? Each prepared feed needs its own bottle or container. The CDC says prepared formula not used within 2 hours should go straight into the fridge, and be used within 24 hours. [4]
5 oz or 8 oz?
Add 8 oz bottles once your baby regularly takes more than about 5 oz at a feed. Not before.
Typical formula amounts, from the AAP: about 1 to 2 oz (30 to 60 ml) per feed in the first week, about 3 to 4 oz (90 to 120 ml) by the end of the first month, and 6 to 8 oz (180 to 240 ml) at each of 4 or 5 feeds by 6 months. [3]
Breastfed babies usually take less. La Leche League puts a typical bottle of breast milk at 2 to 4 oz (60 to 120 ml) from 1 to 6 months, [5] so for a lot of breastfed babies the 5 oz bottle lasts the whole first year.
Nipples are a separate count
One nipple for every bottle in use, in your baby’s flow, plus a spare or two. Nipples wear out before bottles do. Check them before every feed, and replace any that look thin, sticky, swollen or torn. [6]
Some larger bottles come with a faster nipple than your baby uses. If yours did, swap in the slower one.
Pumping and storage
Frozen milk doesn’t need bottles of its own. Bottles are only for the feeds between washes.
To store it, the CDC suggests breast milk bags or clean, food-grade glass or plastic containers with tight-fitting lids. Freeze in 2 to 4 oz portions, or whatever your baby takes at one feed, so less gets thrown out. [7]
Bottles for daycare
Ask your daycare how they want bottles sent. Many want one per feed. Add a spare for the feed that runs long or the bottle that hits the floor.
The CDC advises labeling each container with your baby’s name and the date. [7] Some centers have rules about bottle materials, glass included, so check before you buy a daycare set.
Tuck in a short note too: the flow you use, how much your baby usually takes, and the signs they’re full.
What we would start with
We’d start small if you’re expecting and don’t know yet how feeding will go. It’s easy to add bottles once you have a routine.
- Planning to breastfeed: one 2-pack of 5 oz (160 ml) bottles for the occasional bottle.
- Planning to formula feed or pump: enough 5 oz bottles for the feeds between washes, and a spare.
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Disclosure This guide is published by Ronini, and we sell baby bottles. The feeding numbers come from the CDC, the AAP and La Leche League. The bottle counts are plain arithmetic on those numbers, not a recommendation from any health agency.
Frequently asked questions
How many bottles do I need for a newborn?
About 5 to 7 if your newborn is bottle-fed only and you wash twice a day, since newborns feed 8 to 12 times in 24 hours. Mostly breastfeeding? Two is usually enough.
How many bottles do I need for combination feeding?
Count only the bottle feeds between washes and add one. For one or two bottle feeds a day, that’s 2 or 3 bottles.
Do babies need 4 oz or 8 oz bottles?
Start small, 4 to 5 oz, because early feeds are small. The bigger 8 oz bottle comes in when formula feeds reach 6 to 8 oz, often around 6 months. Plenty of breastfed babies never need it.
How long do babies use small bottles?
Until they regularly take more than the bottle holds. For many formula-fed babies that’s somewhere between 3 and 6 months, as feeds grow toward 6 to 8 oz. Many breastfed babies stay on small bottles.
How many bottles should I send to daycare?
One per feed while you’re apart, plus a spare, unless your daycare asks for something different. Label each with your baby’s name and the date.
Can I reuse a bottle without washing it between feeds?
No. The CDC says to clean bottles after every feed and to throw away formula left in the bottle once the feed is over. Germs grow fast in milk mixed with a baby’s saliva.
References
Sources & references
- [1] Centers for Disease Control and Prevention. How to Clean, Sanitize, and Store Infant Feeding Items. March 2025.
- [2] Centers for Disease Control and Prevention. How Much and How Often to Feed Infant Formula. April 2026.
- [3] American Academy of Pediatrics, HealthyChildren.org. Amount and Schedule of Baby Formula Feedings. May 2022.
- [4] Centers for Disease Control and Prevention. Infant Formula Preparation and Storage. May 2026.
- [5] La Leche League International. Bottles and Other Tools. March 2025.
- [6] Nationwide Children’s Hospital. Choosing a Bottle Flow Rate (Helping Hands HH-IV-244). 2021.
- [7] Centers for Disease Control and Prevention. Breast Milk Storage and Preparation. August 2026.
General information, not medical advice. Your pediatrician knows your baby best. Last reviewed October 11, 2026.
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