Milk & formula storage · Formula in the fridge
How long is formula good in the fridge?
Last reviewed November 2026 against AAP, CDC, NHS and WHO guidance · Sources
Quick answer
Mixed formula is good for up to 24 hours in the fridge, according to the CDC. Put a bottle in the fridge right away if you won't start feeding within 2 hours of mixing it. Never refrigerate formula your baby has already drunk from, and throw it out if you can't remember when you made it.
- In the fridge
- 24 hours
- Refrigerate if not used in
- 2 hours
- Leftovers in the fridge?
- Never
On this page
How long does mixed formula last in the fridge?
Up to 24 hours. The CDC says that if you won't start using prepared formula within 2 hours, store it in the fridge immediately and use it within 24 hours. If you can't remember how long it's been in there, throw it out.
Can I make a day's worth of bottles in the morning?
Yes, as long as the bottles go into the fridge right after mixing and each is used within 24 hours. Write the time you mixed them on the bottles or on a note on the fridge. For babies under 2 months, premature or with weakened immune systems, follow the CDC's extra hot-water steps in how long formula is good for.
Should I keep formula powder in the fridge?
No. The CDC says to store an opened powder container in a cool, dry place with the lid tightly closed, and not in the fridge. More in opened formula.
All formula storage times
| Situation | How long | Then |
|---|---|---|
| Mixed formula, feeding not started | Within 2 hours of mixing | If you won't start within 2 hours, put it straight in the fridge |
| Once your baby starts drinking | Within 1 hour | Throw out anything left in the bottle |
| Mixed formula in the fridge | Within 24 hours | Throw it out if you can't remember when you made it |
| Opened powder container | Most within 1 month (check the label) | Store cool and dry with the lid closed, not in the fridge |
| Ready-to-feed or liquid concentrate, opened | Follow the label | CDC's preparation page gives no time limit |
How do I keep track of the clock at 3am?
Storage rules all start from a time: when you pumped, when it thawed, when you mixed it, when the feed began. Those are exactly the times tired parents forget, especially when someone else made the bottle.
- Label every container of expressed milk with the date (and time, if you'll use it within days).
- Write the mixing time on a formula bottle you've put in the fridge, or tape a note to the fridge.
- Note when each feed starts. That's the clock for the 1-hour formula rule and the 2-hour leftover milk rule.
Feedoo Baby logs the time of every feed and who gave it, so whoever takes the next shift can see when the last bottle started. See how to track baby feeding for a simple routine.
When to call your pediatrician
- A rectal temperature of 100.4°F (38°C) or higher in a baby 3 months or younger. The AAP says to call right away, even if your baby seems otherwise well.
- Fewer wet diapers than expected for their age (fewer than 6 a day from about day 5), or dark yellow urine.
- Very sleepy and hard to wake for feeds, floppy, or unusually quiet.
- Refusing feeds, or feeding poorly several times in a row.
- Signs of dehydration: dry mouth, no tears, or a sunken soft spot on the head.
- Forceful or green vomiting, or vomiting after most feeds.
- Red, black (after the first meconium poops) or white/pale gray poop.
- Yellow skin or eyes that spread or deepen, or any yellow color in the first 24 hours.
- Trouble breathing, blue or gray lips, or your baby is limp or very hard to wake: call 911 (or your local emergency number) now.
If something feels wrong, trust that feeling and call. You never need a reason beyond worry.
Questions parents ask
Can I warm refrigerated formula?
You don't have to, because formula doesn't need to be warmed. If your baby prefers it warm, hold the bottle under warm running water and test it on your wrist. Never use a microwave.
Can I refrigerate a bottle after my baby drank some?
No. The CDC says to throw out formula left in the bottle after a feed and not to refrigerate it for later.
Is formula good after 48 hours in the fridge?
Mixed formula should be used within 24 hours in the fridge, according to the CDC. For opened ready-to-feed or liquid concentrate, follow the label.
Related guides
- How long is formula good for?Mixed formula: use within 2 hours, 1 hour once feeding starts, 24 hours in the fridge. Opened powder: most within 1 month. Every CDC formula rule in one place.
- How long can formula sit out?Mixed formula can sit out up to 2 hours before feeding, and 1 hour once your baby starts drinking. Then throw out leftovers. CDC rules and why.
- How long is formula good after opening?Most opened powdered formula must be used within 1 month, per the CDC. Store it cool and dry, not in the fridge. What to do with ready-to-feed.
- Breast milk storage guidelines: room temperature, fridge and freezerHow long breast milk lasts: 4 hours at room temperature, 4 days in the fridge, 6 to 12 months in the freezer, plus thawed milk and leftover rules from the CDC.
- How to track baby feeding and diapersWhy pediatricians ask about feeds and diapers, exactly what to log for breast, bottle and combo feeding, and paper vs notes app vs tracking app compared.
Free tools
Sources
Last reviewed November 2026. Numbers are ranges from these public health sources; 1 oz ≈ 30 ml.
Feedoo Baby shares general information, not medical advice. Every baby is different. If you're worried about feeding, weight gain, diapers or your baby's health, call your pediatrician, midwife or health visitor.