How Much Detergent Should I Use To Clean My Cloth Diapers?


This is the third and final post about detergent amounts following the story of Emma, a new mom struggling with detergent buildup on her diapers. Emma’s problems were caused by following the detergent recommendations on Fluff Love University, which you can read about in the first post here. Emma figured out she has detergent buildup and removed it following the information in the second post about how to test and remove detergent buildup here

Emma’s now left with the same question she began with: how much detergent do I need to use to wash my cloth diapers? Finding out how much detergent you need for your cloth diapers, is a three-step process including looking at your detergent’s requirements, figuring out your load sizes to matching them to the recommended amounts, and finally adjusting your detergent’s recommended amount to fit special conditions created by your water, illnesses, etc. That’s all. 

Though it’s simple, it can be complex at first when you’re not used to thinking about all the factors that make your laundry unique. Below, I’m going to help you work through each step. To help you along the way, I’ve created a free Detergent Calculator Worksheet you can get here. Once you download the worksheet, I recommend printing it and working through this post, step-by-step. 

WARNING: Reading through this blog post without doing the worksheet at the same time may make it all feel complicated. There are a few steps to go through to figure out your best detergent amount. Although the steps are simple when done one at a time, digesting all the information all at once, without recording each step down on your sheet and moving on mentally to the next one may make it feel overwhelming.

I really recommend working through it as you read. As parents of young children we have enough on our minds! Keeping these steps on your mental task list and not on a paper, may be exhausting. 

Some steps will take you as long as it takes you to look at a detergent label, others may require a bit more time to look something up, so if you’re like me having a sheet handy will be the best way to stay on task while the little ones are tugging at your waistband, shirt, hair, etc. 

As you work through this post, you’ll also be able to see Emma’s worksheet take shape to help you along. At the bottom of the post, there are a few more example worksheets as well. 

Step one: Your Detergent Recommendations

The first step to figuring out how much detergent to use, is NOT to consult the best-intentioned cloth diaper website or Facebook group  (I know, I know).

The first place to look is on the bottle or box of detergent you’re planning on using. 

Each detergent is formulated with a unique ratio of ingredients and therefore the amount needed is different for each one. 

Now as soon as the topic of detergent comes up, one of the first questions I’m asked is, “What detergent should I use?’  So, let’s pause for a minute to address that.

How to Pick a “Cloth Diaper Safe” Laundry Detergent

Choosing a detergent for cloth diapers isn’t as difficult as many make it out to be. There are just three types of detergent to avoid, and anything outside of that is just great whether it be plant-derived, free-and-clear, or super-powered scented commercial detergent in a jumbo box. You can read my full article about Choosing a Cloth Diaper Detergent here, but for now, here are the three things to avoid in short: 

  • No detergents with added softeners. Any detergents with added softeners are a no. Most of these like to advertise the heck out of them and will have, “With the added softness of Downey” or something similar written on the bottle to help you spot them. Baby detergents also commonly have softeners in them. Purex Baby as an example has softeners (Disodium Diaminostilbene Disulfonate) in it. Again, these detergents use “Baby Soft” marketing, which is a big tip-off.
  • No soaps. Homemade laundry soaps, “all-natural soap,” or “cloth diaper soap” and soap nuts are all hard-no’s, they just don’t work. See the detergent post for why they are so useless.
  • No regular detergent if you have an HE machine. The difference between HE detergent and regular detergent goes beyond the amount you need to use. HE detergent is formulated to create less suds. As I have reported elsewhere, too many suds in your machine can not only reduce your machine’s ability to wash detergent away out of your laundry, but can actually harm your washing machine itself, compounding the problem. 

Once again, if you want all the particulars about why all those don’t work, you can check out my post about choosing a detergent here.

Note: Click here if you’re looking for a detergent without optical brighteners.

How Much of the Detergent You Choose Is Recommended?

After you have picked a detergent and taken looked at the bottle for its recommended amount, you’ll notice that there are different load sizes and possibly soil levels listed. You’ll want to record these on your worksheet for later. 

Worksheet Step One:
Record your detergent bottle recommendations on the worksheet.

Emma, our example, uses Purex Dirt Lift, which she buys at Costco for a reasonable price, and stocks up when it goes on sale.

I like Purex as an example because it also allows me to explain that the label on Purex Dirt Lift bought at Costco (which shows an illustrated cap with three lines) does not match up with the actual cap you get (which has five lines). To help anyone using this detergent I’ve contacted Purex and was told to follow the label, and then use line 4 and 5 for larger AND heavily soiled loads. Taking that advice, here’s what I follow: Small load = line 1, medium load = line 2, large load, (using 21 lbs as the load size, which we’ll talk about later) = line 4.

Emma’s Worksheet: Step One

The amounts you just recorded, the ones on your detergent bottle are your starting point for everything else. All the other information we collect is just to tweak those amounts and how much we’re throwing in the machine with our detergent.

Tide Users: Don’t get stuck on the wording, record the three levels on your bottle/box in the appropriate spaces even though they are called “medium” “large” and “full.”

So Which of the Three Detergent Levels Do You Choose? 

To start, we can assume that all cloth diaper laundry is “heavily soiled.” Unlike regular laundry, which usually consists of surface dirt on top of a single layer of fabric, cloth diapers are multi-layered with urine and feces soaked deep in. But aside from being really dirty, there are a couple of other factors to consider when choosing what detergent level is right for your load of diapers. 

This is where your machine, load size, and other factors start to make things a bit more complicated. Without this information, any detergent amount you choose (and any recommendation someone else gives you) will just be a shot in the dark. 

I repeat, without considering your machiene, load size, and other factors like water conditions, any detergent amount you choose (and any recommendation someone randomly gives you) will just be a shot in the dark. 

So let’s shed some light on what your unique situation is, so that you can choose the recommended detergent amount that’s closest to your needs. 

Worksheet Step Two:
Calculate Your Load Sizes

Step Two: Load Sizes

As you’ll see on the worksheet (you can grab it here if you haven’t already), there are two things that influence your load size: 1) how big your washing machine drum is; and 2) how many diapers you’ll be washing.

Let’s take a look at each:

How Big Your Washing Machine Drum Is

Washing machines come in all sizes, so a full or even partial load in one can be vastly different than another. 

Also, if there’s one thing I’ve learned while researching this article, it’s that the labels “super capacity,” “large capacity,” etc. mean absolutely nothing. 

Meaningful measurements for load sizes are done by weight. Your machine may or may not provide the weight allowance, but it will usually provide the cubic foot measurement of the drum, which can be converted to lbs. 

According to Samsung:

“-A small load of laundry is approximately 1 pound of laundry per cubic foot of the washer’s capacity or when the tub is 1/3 full.

-A medium load of laundry is approximately 2 pounds of laundry per cubic foot of the washer’s capacity or when the tub is 1/2 full.

-A large load of laundry is approximately 3 pounds of laundry per cubic foot of the washer’s capacity or when the tub is 3/4 full.

For instance, a washer with 4.0 cubic feet capacity would consider a 4-pound load small, an 8-pound load medium, and a 12 pound load large.”

Note: The minimum recommended weight for the washer is 3 pounds. Machine washable wool items should be limited to 4.4 pounds or less. Comforters and blankets should be limited to 6.6 pounds or less.

Using these weights as a reference, we can see just how widely washer sizes can vary. Let’s take a look at these three examples:

Avalon Bay EcowashBosch High-Efficiency Compact Front-Loading WasherSamsung VRT Top Loader
A hand-crank, non-electric portable washer with a 5 lb capacity. An HE washer that has a 2.2 cubic feet capacity. A 4.5 cu. ft. capacity HE top-loader.
Five lbs of laundry would be an x-large load as that’s its maximum.
*Note it is of course not high efficiency.
A large load would be about 6.6 lbs. A large load can be up to 13.5 lbs. 
Click here to see specifications on AmazonClick here to see specifications on Best BuyClick here to see specifications on Samsung.com

To me, this table illustrates why it’s so important to know the size of your machine.

While it might be a no-brainer that the small hand-crank washer needs less detergent for a full load, it may not be so clear to the owner of the Bosch and the owner of the Samsung that a “full load” of laundry would be very different for each of those machines. In fact the Bosch holds less than half the amount of the Samsung in this comparison!

It’s important to know the size of your machine so that you can create load sizes that optimize your diaper laundry and make sure that you’re not over-stuffing your maximum loads, or not putting enough diapers in for a minimum load.  

If you can, find out the max. size of your washing machine online and record it on your worksheet. If you can only find the cubic feet of the drum, use the calculation from Samsung above to give you an approx. max. weight. 

If you can’t find either, doing some testing to see how much it takes to fill your laundry tub to the ⅓, ½ and ¾ mark may be helpful. But at the very least, use those measurements as a guide.

Emma has the Samsung VRT Top Loader in the chart above, and therefore her calculator worksheet looks like this:

Emma’s Worksheet: Step Two (washer capacity)

BUT WAIT! How Much do Cloth Diapers Weigh? How Many Cloth Diapers Can I Fit in My Washer?  

Of course, even if you have a large capacity washing machine, that doesn’t always mean you’re going to fill it up all the way.  

As I mentioned earlier, here are two things that influence your load size: 1) how big your washing machine drum is; and 2) how many diapers you’ll be washing.

You need to know how big your washer is first to know how many diapers you can wash in your machine while meeting the minimum weight for a small load, and staying under the maximum weight of a large load.

Now, that you do know what your max. and min. loads are in your washer, let’s find out how much your diapers weigh.

Below, I have some average diaper weights that you can use to give you a rough estimate.

These weights are just estimations for you to get a good idea of how much your load of diapers will weigh, along with some common household items just in case you’re washing your diapers with other laundry (you can read my post about washing diapers with other laundry here). 

They are based off the helpful list of cloth diaper weights at AllAboutClothDiapers.com, as well as information from The Spruce.  Of course every diaper will weigh a little more or less based on brand, age, etc. but this is to give you an estimate only. One or two diapers either more or less won’t usually throw things off very much, but as you can see a handful of diapers more or less can change your load weight dramatically.

ItemWeight (see note below)
T-shirt
o.5 lbs
Jeans1.6 lbs
Large bath (or beach) towel1.6 lbs
All-in-one’s (AIO)0.75 lbs
Prefolds, Flats & Flour Sack Towels (FST)*
*Covers won’t add much weight but it’s factored in as rounding up
0.6 lbs
Fitteds, Hybrid Fitteds & Overnight Fitteds*
*Covers won’t add much weight but it’s factored in as rounding up
1.4 lbs
Pockets & All-in-two’s (AI2)Use insert weights below based on the number of inserts, doublers, etc. you use per diaper and round up for the small weight of the pocket and AI2 covers.
Inserts, Doublers & Boosters0.37 lbs

Note: Weights for clothing and other non-diaper laundry are dry weights, whereas weights for diapers are wet weights as, most of the time, that is how they will be when placed in the washing machine, and therefore how your HE machiene will sense them to calculate the water needed for the load.

Ok, I Have my Washer Size and Know How Much My Diapers Weigh! Now what?

The last piece of info we need to finish up step two of your worksheet, is to know how often you plan to wash and/or how many diapers you’ll have to wash each laundry day.

Knowing how often you plan on washing your diapers is important. If you’ve already been using cloth for a while, you’re ahead of the game because you likely know how often you wash, and how many diapers you’re washing each load, roughly.

If you’re doing all of this in advance of baby’s arrival and have no clue how many diapers you’ll have to wash, you can use this post about how many diapers your baby will use as a guildeline. If you know what style of diapers you’re going to use, and how often you want to wash, these guidelines will help you come up with a solid plan.

So using the diaper weights chart above, you can see that if we washed every two days, giving us two days worth of pocket diapers to wash, with a mix of inserts, for our baby who dirties a diaper every three hours or so during the day (so let’s say roughly 10 daytime diapers over two days with 4 extra inserts), and two fitted diapers with covers for nighttime, we’d calculate:

Ten Pocket Diapers, with 4 extra inserts (for naptimes in this made-up scenario I’m creating) = about  5.2 lbs
Two fitted diapers = 2.8 lbs
Total dirty diaper laundry weight = 8 lbs

If you hate math: I hear you, mama-brain-fog is real, and math is a chore on the best day for many of us. If you want to cut down on the math, weigh yourself on your home scale, pick up your full diaper laundry pail liner or hanging bag (just before you would normally do a load) and weigh yourself again. The difference between the two weights is how much your diaper laundry weighs.

Now, Let’s Put It All Together

Ok, so we know how big your washer’s recommended loads are, we know how much your load of dirty diapers weighs, so, all that’s left is to figure out what load combination works best for you!

So say you have a washer with a small load weight of 2.2 lbs, a medium load of 4.4 lbs and a large load of 6.6 lbs. If you’re the person with 8 lbs of dirty diaper laundry above, you wouldn’t want to do them all in one load because that’s too heavy for your max load, but two loads of about 4 lbs each is perfect for your washer!

I hope this was the lightbulb moment for you that it was for me!

By truly knowing how much laundry you have, compared to how much laundry your machine can handle, you can make much better washing decisions!

I should also note, if baby is older, or if you’re only doing cloth part time and don’t have enough to wash to meet your minimum load weight for your washer, you CAN wash them with regular clothing, but as I’ve written about before here, you will want to be a little careful about what types of clothing you’re washing them with. 

BUT WAIT! What Does All That Mean for Detergent?

So how do you know how much detergent your load(s) need then? That’s a great question, and one that detergent makers don’t seem keen on opening up about, however I was able to get some information from Tide.ca on what detergent makers consider a small, medium, and x-large load. Here are two great graphics showing the weights for each:

Special Note: While Tide considers an x-large load to be about 22 lbs, it’s rare to find a washer with that capacity for the home. I was also unable to find detergent information elsewhere for loads that large. Most sources site capacities for very large top-loading home washers as about 13-15 lbs. Because of this, if you’re not using Tide, I would consider an x-large load to be about 15 lbs. If you are using Tide, take note that their large load is supposed to clean way more than your machiene can clean at one time! This is of course for regular laundry, and not heavily-soiled diapers, but still!

So Now, Your Detergent Level Should be Accurate

So, after all that work, you should be able to match up your ideal load size to your detergent’s recommended amounts a bit more accurately. Let’s take a look at Emma’s worksheet Step 2:

Emma’s Worksheet: Step Two

So we can see that her load size works out to just about the perfect large load of laundry for her machiene. BUT that weight is still well below the 21 lbs of a large load detergent level, so Emma would probibly be best to use a level a little bit below that, but more than a medium load… so she lands on line 3 of her detergent as her ideal detergent level for her load of laundry in her machiene.

Is That It? I’m Done?

Possibly. But there is still one thing we need to cover that MAY make you need adjust your detergent level away from what you determined in step two: very hard or soft water.

Worksheet Step Three:
Adjust for Your Water Conditions

If you’ve been researching cloth diapers for a bit, you’ve probably heard a lot of talk about hard and soft water in the cloth diaper space before, and that’s for a good reason. Water hardness or softness is directly linked to how much detergent you need. 

Hard water is water that has high levels of calcium and magnesium minerals. Roughly 85 per cent of the United States has hard water. The more calcium and magnesium in your water, the harder it is.

I won’t go too far down the rabbit-hole of why hard water matters in this post (you’ve read enough) but in a nutshell, it’s all about finding a balance so that everything can get rinsed away: soap, dirt, and minerals. If you have hard water, more soap is needed to wash the minerals away along with the dirt. If you have soft water, less soap is needed and more water can be used to make sure the soap is rinsed away.

You can find out if you have hard water fairly easily. If you’re on a municipal water system, your city’s website or telephone service should have information about your water hardness/softness they can share with you.

If your city isn’t easily accessible, or if you’re on a well system, testing for hard water is actually pretty quick and easy. Many spa and pool retailers will test your water for you for free or a very small fee. Or you just need to get yourself some water test strips.

I found these ones on Amazon, which are very inexpensive, and are some of the easiest to read that I’ve found. 

Test kits like this one are usually available at pool and spa retailers as well, though they may come in larger quantities, test for multiple things, and therefore cost more. Getting the most expensive test is not really needed for laundry purposes, you’re just looking for a result you can easily read that will give you a solid enough range to adjust your detergent level in the right direction.

To use them, you just dip them in the water and they change color according to how much mineral content hits them. By following the instructions on the package, you’ll get a good idea of what range your water falls into.  

You’ll see on your Detergent Calculator Worksheet a bar under step two where you can record your test results. You can circle, or star, draw a dinosaur, or whatever your specific test kit puts your reading. In general, the center of the scale, or water that’s neither too soft or too hard, is usually about 85-100 ppm (parts per million).

As you’ll see on the sheet, the harder your water is, the more detergent you’ll need, and the softer it is the less you’ll need. Again, I speak to the why of that in another post (you’ve read enough for now!). For very hard water at the left of center, you’re going to want to add up to 30% more detergent, and for soft water, you’re going to want to reduce it up to 30%.

For water around the center (85-100 ppm) you’re going to leave things as it and use the recommended amount on the bottle for your load size that we calculated above.

Let’s take a look at Emma’s sheet one last time:

Emma’s Worksheet: Adjustments

Emma has a water hardness reading of about 50PPM, which is on the soft side. Because her load size is also just two lbs or so away from the medium load weight for detergents, she decides to reduce her detergent level to line 2.
To put it another way, because her water is soft, Emma reduces her detergent amount to the amount needed for about 11lbs of laundry, even though her load size is about 13.23 lbs.

A Quick Note About Prewashing

Some of you who have been researching cloth diapers for a while may be wondering about pre-wash detergent amounts. I’m not going to go in-depth about that here, but in general, I don’t recommend prewashing with detergent unless you have very hard water (over 160 PPM).

Prewashing with detergent is one of those things that’s gets suggested because it sounds good, but there’s no information to back it up that I can find. In fact, if you have soft water, and prewash with detergent, you’re likely going to get buildup.

If you have very hard water (over 180 ppm) prewashing with detergent is ok. If you don’t, skip the detergent in your prewash, and just focus on getting the amount in your main wash right.

I will have more on this in future posts, if you really want to get into that topic, and I’ll link to them here.

How Do I Know if I Got it Right? 

Now that you know just how many factors affect how much detergent you need to use, you are likely thinking, “Whoa, what if I get something wrong? How do I know if I got it right?”

First off, it’s ok if you miscalculate, a little. 

I know we want everything to be perfect for our cloth diapering journey, but it’s also important not to think of this cloth diaper thing in absolutes.

There may be times where the amount you land on doesn’t work and something happens, you get a dingy diaper, or worse, a stinky diaper. While it’s unlikely using this method that you’ll find yourself in a horribly bad situation, things can happen, but with your worksheet in hand, I’m also confident you’ll have a much better idea about what went wrong and be able to fix it with just a small adjustment.

Encountering an issue after following a random recommendation online and not knowing what could have went wrong is very different than having an issue, looking at your sheet and being able to say, ‘Hmm, maybe I should be bumping up my detergent one line because maybe I went down too low for my water softness.’

Knowledge is power.

What if This is All Too Much?

I get it. I’m asking you to consider a lot of things in this post, just for a simple detergent amount that you can count on. It’s a lot to add to a parent or guardian’s plate. It’s also a lot to jam into one post.

If it’s too much for you, I am releasing a Wash and Care Handbook on May 13, 2020, which takes you through all of this information with much more explanation, and at a much slower, step-by-step pace.

In that book, I also cover care information like drying, troubleshooting, stain-fighting, making diapers last longer, and much more.  If you’re needing more of a step-by-step approach, you’re totally not alone. After all, I wouldn’t have spent so much of my time making the handbook if I didn’t hear that people needed it!

I will have more information on website about the book when it launches, until then, if you preorder the book before it launches on May 13, 2020, you can use this special sale link to get 45% off the cover price. ($5.49 instead of the regular price of $9.99).

My goal with the book was to take the mystery, fear, and ridiculous rules out of cloth diaper washing. If you’re looking for more information about the book, the Cloth Diapers for Beginners Wash & Care Handbook, you can check out the table of contents here, but to get the special 45% off discount you must preorder through the sale page:

Either way, I hope all of this helps you in your cloth diaper journey!

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