When mixing baby formula, it’s important to follow the instructions on the container.
Why? Because mixing it with too little water or too much water can mess with your baby’s sodium levels and cause problems (think: seizures).
Here are the Formula-Mixing Specifics:
As You May (or May Not) Know, There are 3 Main Types of Baby Formula. They Are:
1. Powdered Formula (the most commonly used type of formula).
2. Liquid Concentrate Formula.
3. Ready-to-Feed Formula.
Both Powdered Formula and Liquid Concentrate Formula must be mixed with water, whereas Ready-to-Feed Formula (as the name implies) is ready to go (i.e. no mixing required). Just shake the bottle, pop the top, and serve.
Below are the Generally Accepted Mixing Ratios For Powdered Formula and Liquid Concentrate Formula.
Disclaimer: Always read the label on the formula container to ensure proper mixing.
1. Powdered Formula
- Formula to Water Ratio: 1 : 2
- Here’s a Sample Recipe: 1 scoop of powdered formula + 2 ounces of water. Then shake and serve (bon appétit!).
Note: 1 ounce = 30 milliliters, so 2 ounces = 60 milliliters.
- PediaTips:
- Make sure the scoop of powdered formula is level (not overflowing) and unpacked (i.e. not super compressed and packed down).
- If you have to feed on the run, you can plan ahead by adding the desired number of scoops of powdered formula to a dry bottle. When it’s time for your baby to eat, just add the correct amount of water, shake, and feed.
- Make sure the scoop of powdered formula is level (not overflowing) and unpacked (i.e. not super compressed and packed down).
2. Liquid Concentrate Formula
- Formula to Water Ratio: 1 : 1
Heads Up: The mixing ratio for liquid concentrate formula and powdered formula is NOT the same.
- Sample Recipe: 1 ounce of liquid formula + 1 ounce of water. Then shake and feed.
Important Things to Know:
- Prepared formula (of any kind) should NOT be left out at room temperature for more than 1 hour. After an hour, it should be discarded. If you plan to refrigerate the formula, you must do so within the hour.
- After your baby has had their fill of formula, any leftover formula in the bottle should be thrown away.
Why? Because it now has your baby’s germs in it (from spit-back).
- Freshly prepared powdered formula can be safely stored in the fridge for up to 24 hours, whereas freshly prepared liquid concentrate formula and open bottles of ready-to-feed formula can be stored in the fridge for up to 48 hours.
Common Questions About Mixing Baby Formulas
Should I Mix My Baby’s Formula With Filtered Tap Water or Bottled Water?
Although we tend to love our bottled water in the U.S., filtered tap water (from a safe source) is actually a better choice for babies because it contains regulated amounts of fluoride.
Bottled water, on the other hand, doesn’t naturally contain fluoride. Even if you see bottled water with added fluoride, it’s still better (and cheaper) to opt for filtered tap water because the amount of fluoride in it is more carefully controlled.
PediaTip: Call your local water company to ask about the quality of the water in your area. If you have iffy tap water or use well water, ask your baby’s doctor if you should boil the water prior to using it OR just use bottled water.
Speaking of Boiling Water…Should I Boil the Tap Water That I Mix With the Formula?
Whether (or not) to boil the tap water before adding it to the formula is actually a bit of a controversial topic. You’ll see various opinions about this topic online and may even hear doctors give conflicting advice about what to do.
The American Academy of Pediatrics’ Current Recs on This Topic are as Follows:
- If the water you’re mixing with the formula is from a “safe water source as defined by the state or local health department,” then you do NOT have to boil the water beforehand.1
- However, if you have any concerns about the safety of your tap water, use bottled water or bring the tap water to a “rolling boil” for 1 minute (no longer) prior to use. Let the water cool for no more than 30 minutes before mixing it with the formula. You can test the temperature of the mixed formula by shaking a few drops of it on the inside of your wrist.
- If your child’s doctor recommends boiling the tap water or bottled water regardless of the safety of your water source, then go with what they say.
- PediaTip: Make sure to sterilize your baby’s bottles before adding any formula to them.
The Bottom Line
Be careful when mixing your baby’s formula. Refer to the above guidelines for general mixing instructions, but always make sure to read the directions on the formula container. In addition, ask your baby’s doctor what type of water (tap vs. bottled, boiled vs. not boiled) they recommend, based on where you live.
