Baby Formula Mixed Wrong: Now What?

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effects of too much baby formula

I remember the days of mixing formula extremely well.

We used to make big jugs of formula at night that would give us plenty for the next day.

The process was simple, but treacherous: Fill the jug with the right amount of water, carefully count out the scoops of formula, stir thoroughly.

But, WITHOUT FAIL, one of us would accidentally start talking to the other during the counting phase. Or the phone would ring. Or someone would knock at the door. Or the dog would bark.

It is so, so easy to lose track of how many scoops of formula you’ve used and accidentally dilute the formula or put an extra scoop (or several) of formula in it.

So what do you do if you mixed the baby formula wrong? If you put too much or too little baby formula in the mixture?

The answer: Take a deep breath. Everything is (probably) going to be OK.

There’s a lot more to it, and plenty of relevant information you’re going to want to check out, so you can skip to the section relevant to you, here:

And if you’re really worried, and/or your baby is showing signs of distress after drinking improperly mixed formula, I’d skip this article and call a doctor.

If you keep having problems mixing formula correctly, I HIGHLY recommend you check out the Baby Brezza — it’s like a high-tech coffee machine for formula. Just fill it up with water and powder and it dispenses perfectly mixed formula at the perfect temperature, every time.

Click to see the Baby Brezza on Amazon.

Why it’s easy to accidentally dilute or over concentrate baby formula

If you’re using powdered formula, it seems simple enough:

Usually 1 scoop of formula per 2oz of water is the perfect amount, though you should always go exactly by what it says on the side of your formula container.

(Pre-made formula, aka ready to drink, should never have any water or powder added to it.)

But it’s ridiculously easy to get distracted and lose track during the counting or mixing process.

Even if you’re just making enough formula for one bottle (so only a few scoops of dry powder!), you’d be surprised how easily you can just simply forget whether you’ve dropped in one scoop or two.

(Especially when wrangling a potentially fussy baby)

For small servings or single bottles, it’s pretty easy to accidentally be off by 1 or 2 scoops.

When you’re making a big jug ahead of time, and counting out around 12 scoops, there’s a ton of room for error if you get distracted.

In both cases, you’ll usually know right away if you’ve lost track of counting the dry scoops of formula, and sometimes you’ll be able to figure out where you got tripped up.

Other times, you’ll finish the whole process and just have no idea, like your mind was on autopilot the whole time.

The bottom line is that if you’re unsure, the safest thing is to dump the whole thing out and start over.

But, I am also a human being who doesn’t have unlimited money, and I know dumping out a pitcher of 24 ounces of formula can really hurt the wallet (it might even be all you currently have in the house).

In that case, below we’ll dive in a little deeper to whether you should think about still using that formula.

Effects of too much baby formula (over concentrated)

If you’ve fed your baby (or are thinking about feeding) formula that might be a little over concentrated, here’s what you should know.

The main things to look out for in this scenario are constipation and dehydration.

A little, tiny bit of extra formula is probably not a huge deal… after all, it’s just more nutrition and calories. But if there’s so much dry formula in the mixture that the baby isn’t getting enough water, constipation and/or dehydration can set in.

It’s probably unlikely if you’re only off by a little bit, but here are some signs to look for that your baby might be dehydrated or constipated:

  • Sleepiness
  • Irritability
  • Thirst
  • Sunken eyes
  • Decrease or absence of tears
  • Dry mouth
  • Fewer wet diapers

Constipation is a little easier to spot in babies. If they’re not going at least once a day (and that’s the bare minimum… younger babies often go far more frequently) they may be constipated.

Both would likely require a trip to the doctor, where they might place your baby on fluids like Pedialyte to rehydrate them. (I’m not prescribing this, just telling you what might happen.)

So should you use over-concentrated formula?

I’m not going to tell you that’s it totally fine and nothing bad will happen. The safest thing to do would be to dump it out and start over, and pay careful attention this time.

But I haven’t seen anything in my research to suggest that an extra scoop or two of formula, on the rare occasion, would be fatal or even that damaging.

Again, consult a doctor to know for sure.

Effects of watered down (accidentally diluted) baby formula

On the other end of the spectrum you have formula that has too little powder mixed into it and too much water content.

The main concerns with this kind of wrongly mixed formula are that it’s going to be low on calories and nutrition, and that the water content may be too high.

The horror stories you hear about are often when people chronically feed their baby diluted formula to save money, or just give them water to drink before they’re of age. (Don’t ever, ever do this!)

On a rare occasion that the formula doesn’t have all the nutrients it should, your baby will probably just get hungry a little earlier than usual.

(A note on water: You’ve probably heard that babies shouldn’t drink water, and that’s true of babies younger than about 6 months.

But it’s not so much that water is bad for them.. they do need hydration, after all, they just usually get it from formula and milk… it just can cause other problems like interfering with their ability to get nutrients from milk or formula, or tricking them into thinking they’re full and depriving them of needed calories.

(In rarer and more extreme cases, it can cause something called water intoxication. But that’s probably out of the scope of this article and is very unlikely to happen with formula unless you just completely forgot to put ANY formula powder in the bottle, or if the formula is super diluted and your baby is very, very tiny.)

If you’re a little bit off on the formula mix and you accidentally dilute or water down the mixture by a small margin, it’s most likely not going to be a big deal as a one-off.

Important: If you think the formula is severely watered down and/or if your baby is very, very young or a newborn, I’d be much more careful. Definitely call your doctor if you think your 6-months-and-under baby may have drank too much watery formula.

(Scroll down for more on this.)

After feeding: What to do if you have no idea how many scoops were in the mixture

I totally get it. You’re not a bad parent. I promise.

Look around parenting discussion boards and you’ll be amazed at how frequently this happens to people.

If you space out for a minute while creating the mixture, and then feed it to your baby, it’s asking a lot for you to know exactly how many scoops over or under you went.

Sometimes it’s just impossible to know, with how chaotic things are, and how sleep deprived you’ll probably be.

So… you just fed your baby formula, and you’re pretty sure you mixed it wrong, but you can’t say for sure.

Now what?

The first thing is to not freak out. We’ve already talked about how a little formula miscalculation is probably not the end of the world as an isolated incident.

The second thing is to closely monitor your baby for any change in behavior, mood, and especially the above symptoms of constipation and dehydration (scroll up to see them again).

The third thing is to call a specialist, if you feel the need to. If you’re not ready to involve your doctor, many formula brands have hotlines where you can talk to feeding experts that know all about the effects of baby formula and should be able to help you. It should be listed on the side of the formula container.

(The number for the Similac hotline is 800-986-8800, for 1 on 1 feeding and information service.)

If you’re really concerned, and you think your baby is showing signs of, well, anything, skip right to calling your doctor or doctor’s office answering service during off-hours.

Before feeding: When in doubt, throw it out

OK, so you just mixed up some formula, and you can’t remember how many scoops you put in.

But you haven’t fed it to the baby yet.

Can you still use it?

Well, one thing you can do is a visual inspection (i.e., how to tell if formula is OK by looking at it):

  • If it’s noticeably thicker than usual, don’t use it
  • If it’s noticeably paler and more watery than usual, don’t use it
  • If you can’t really tell a difference, it’s probably in the middle range and not too far off of where it should be

One bottle that’s a tiny bit off-ratio isn’t the end of the world in all likelihood, but if you made an entire jug wrong, or aren’t sure what’s in it… you’ve got to dump it.

I know, it sucks, and it costs a lot of money. But you’re really playing with fire by feeding your baby like 6 bottles in a row that might be off.

It’s just not worth it.

When in doubt, throw it out.

Tips to mix baby formula perfectly, every single time

OK, so, I think we can agree that there’s a lot of gray area here and the best thing would be if this never happened again.


A couple of tips that helped me and that I’ve borrowed from discussion forums all over the web:

1. Pre-portion your formula out into little containers for much easier tracking 

Click to see these formula containers on Amazon

Check out this great set from Munchkin on Amazon.

Fill these up ahead of time (when things are calm) and grab them when it’s time to make a bottle.

That way, you’ll always know you have the right amount of powder without having to count again.

2. Use a formula mixing pitcher to make your formula in bulk

Make the day’s formula all at once using a big mixing pitcher.

That way, you only have to focus and count properly ONCE and then you’re done. In times of chaos later in the day, you can simply pour from the premade jug you’ve kept in the fridge.

Here’s my favorite formula mixing pitcher on Amazon.

3. When counting scoops, count OUT LOUD and not in your head

Schedule the right time to do it, if possible. Maybe make up a pitcher last thing before bed when the house is quiet and there are no distractions.

Tally each scoop on a piece of scrap paper as you add them, if that helps. If you get distracted and lose count, you’ll know exactly where you were.

4. Start using a Baby Brezza formula dispenser

Click to see the Baby Brezza on Amazon

These things are absolutely incredible.

Think a high-tech coffee maker, but for baby formula. Just fill it with water and dry formula, press some buttons, and it does the rest on-demand.


Check out the Baby Brezza on Amazon.

Do you have any favorite tips for not losing focus while counting formula scoops? Share in the comments!

These seem like overkill in some cases, but it’s much better if you don’t find yourself having to choose between wasting expensive formula and potentially putting your baby at risk.

Wrapping Up

The biggest thing to avoid is chronically, repeatedly feeding your baby formula that’s been mixed wrong, over-concentrated, or diluted. Whether that’s due to carelessness of an attempt to save money.

In most cases, screwing up one time won’t cause significant problems.

I would definitely urge you to not use a full pitcher that’s been mixed wrong, because that compounds the problem across 6-8 bottles, and could be a risky move.

And I’ll end with this: When in doubt, throw it out and start over.

Formula is expensive, but you wouldn’t want to make a bad decision because you were worried about pinching pennies.

And while I hope this information and research has helped you, please call a doctor or feeding specialist of some kind if you’re really worried after feeding questionable formula to your baby.

Good luck, parents!