How long does baby formula last?


When you’re formula feeding your baby, it may seem like you’re making formula all the time. Babies eat often, and their tiny stomachs can only hold so much at once. When your little one constantly wants another bottle, it can be tempting to make a large batch of baby formula and have a few days worth ready to go. 

If you’ve been wondering how long baby formula lasts and how you can make the most of it, we have all the answers below.

The type of formula matters


Powered formula is mixed with water to make a bottle. Unopened, you can rely on the expiration date listed on your formula container. Sealed containers shouldn’t be refrigerated before use. Instead, you should keep them in a cool, dry place until you are ready to use them.1

Once a powdered formula container is opened, it should be used within 1 month. It’s a good idea to keep a pen or marker near where you store your formula so you can write the date you open the container on the lid.1

Room Temperature: Once a bottle is prepared it should be stored in the fridge within 1 hour if you don’t feed it to your baby. If it’s been out for longer than 1 hour it should be discarded.2

If your baby drinks from a bottle, any leftover should be discarded. You never want to save a bottle your baby drank from because it can be contaminated with their germs.

Refrigerated: Baby formula made from powder lasts up to 24 hours once refrigerated.2

Concentrate and ready-to-feed

Liquid concentrate formula needs water added to make a bottle and ready-to-feed formula can be given just as it is.3

Room Temperature:  Like powdered formula, concentrate and ready-to-feed formula last 1 hour at room temperature and bottles should be thrown away instead of stored in the fridge if your baby drinks from them.2

Refrigerated: Bottles prepared from liquid concentrate and open containers of ready-to-feed formula can be stored in the fridge for up to 48 hours.2

What about expiration dates?

The expiration date printed on your formula container tells you when you shouldn’t use it anymore if it hasn’t been opened. 

For example, a container of powdered formula may have an expiration date of one year from the date of purchase. This means the powder is good for up to one year if you haven’t opened it yet, but most formulas need to be used within 1 month of opening the container. Always be sure to read the label of your formula to see what it says about this.1

Why does formula go bad so quickly?

Your infant’s formula expires quickly because it’s made from milk. And like the milk in a carton we’re familiar with in the grocery store, it can become infected with bacteria if it’s not stored correctly.1

Can you refrigerate partially-used bottles?

No! If you begin bottle feeding and your baby leaves some formula behind, the leftover needs to be discarded within the hour. When your baby drinks from a bottle, bacteria from their mouth can get into the bottle, so these bottles shouldn’t be saved.

Can you freeze formula?

The short answer is no, you shouldn’t freeze formula. Freezing infant formula is not recommended because this can make the formula’s components separate.4

What’s the best way to warm bottles?

There are a few ways you can warm up formula that’s been refrigerated for your baby. Just remember cold formula is perfectly safe for babies, so you don’t have to heat a bottle if your baby is happy to take it cold.

One way to warm a bottle is to run it under warm water. Another way is to place it in a bowl of warm water. Or if you have a bottle warmer, that works too. Most importantly, never microwave formula because this can make hot spots that burn your baby’s mouth.5

Be sure to check the bottle’s temperature before feeding it to your baby by testing a few drops on the inside of your wrist.5

How do I make baby formula?

Powder formula: Most powdered formula is mixed by adding 2oz. of water for every scoop of formula. Water should go in the bottle first so it can be measured properly and then powder should be added. Be sure to use level scoops and always follow the manufacturer’s directions on the container.

Liquid concentrate: Most liquid concentrate is mixed as 1oz of concentrate to 1oz of water. Again, always be sure to read the instructions on the label of whichever formula you’re using to confirm the mixing directions.

Can I make formula to give my baby later?

In general, it’s always best to make bottles right before you are going to feed them to your baby. However, this isn’t always practical, especially in the middle of the night, so if you need to make a bottle in advance just be sure to follow the instruction above for refrigerating it.6


There are a few important things to keep in mind when feeding your baby formula:

  • Be sure to use prepared, refrigerated formula within 24 hours
  • Always read the label for specific instructions
  • Store unused formula in the fridge within 1 hour of mixing
  • Discard any leftover formula from a bottle your baby drank from
  • Heat bottles safely and never in the microwave


1-Infant formula preparation and storage | Centers for Disease Control and Prevention

2-How to safely prepare formula with water | American Academy of Pediatrics

3-Bottle-feeding (formula) questions | Seattle Children’s

4-Infant formula: safety do’s and don’t | Food and Drug Administration

5-Formula feeding FAQs: preparation and storage | Nemours Kids Health

6- Feeding your infant: how to prepare and store baby formula | Cleveland Clinic

The content on this site is for informational purposes only and not intended to be a substitute for professional medical advice, diagnosis or treatment. Discuss any health or feeding concerns with your infant's pediatrician. Never disregard professional medical advice or delay it based on the content on this page.

The content on this site is for informational purposes only and not intended to be a substitute for professional medical advice, diagnosis or treatment. Discuss any health or feeding concerns with your infant’s pediatrician. Never disregard professional medical advice or delay it based on the content on this page.

Meet the Author

Morgan Leafe

Morgan Leafe, MD, MHA, is a medical writer and editor who is double board certified in Pediatrics and Clinical Informatics with 14 years of clinical experience caring for pediatric patients and their families. She specializes in writing both patient-facing and clinician-facing material.

  • Milk Drunk Weekly

    Need a good read while you feed? Keep in the loop with the top pieces from the Milk Drunk team.