BumGenius 4.0 One Size Diaper Review

bumGenius 4.0 One-Size Cloth Diaper

Those of you who follow my blog know that my BumGenius diaper sprayer is possibly my favorite cloth diapering accessory. To be honest, I cannot imagine using cloth diapers without it. I try to have as little contact with soiling as possible, so the dunk and swish method hold no appeal for me.


bumGenius 4.0 Features


  • Durable snap closures help keep diapers on older babies.
  • Generous sizing accommodates larger babies.
  • Easily replaceable elastic keeps your diapers fresh.
  • 3×3 snap down design* adjusts the sizing to fit small, medium and large sizes (approximately 7-35+ pounds).
  • Trim, snug, and comfortable stretchy tabs* provide a custom fit.
  • Waterproof insert stopper* prevents leaking at the tummy.
  • Diapers are bundled with two inserts: a newborn insert for newborns and a one-size insert for your older baby.
  • Wide slot opening makes it easy to stuff and remove insert.
  • Slot cover* protects your baby from wetness.


With bumGenius 4.0 Cloth Diapering Has Never Been So Easy

bumGenius One-Size Cloth Diapers feature a patent-pending butterfly closure system to provide a comfortable, trim fit. This simple design makes cloth diapering as easy as using disposables. The familiar design makes bumGenius one-size cloth diapers perfect for care providers who might be resistant to cloth diapering (including daycares).

bumGenius One-Size Cloth Diapers MEans Less Clutter

bumGenius One-Size Cloth Diapers fit most babies from 7 to 35+ pounds. No more sorting by size or having to carry multiple diapers when going out. Three snap-downs on the front of the diaper* allow you to easily adjust the size of the diaper as your baby grows. For newborns, fold down the insert stopper for an extra-small rise.

Only The Best For Your Baby

The soft, waterproof outer fabric keeps the diaper trim on your newborn and toddler. Soft, sueded inner fabric gently wicks moisture away from your baby’s skin. Super stretchy, gentle leg and back elastic with rolled out casings keeps the yuk in and help to keep red marks away. Our unique covered* slot opening keeps your baby protected from moisture.
Bumgenius 40 Sizing

BumGenius 4.0 Vast Improvement Over BumGenius 3.0

BumGenius 4.0 one size diapers are a vast improvement over the BumGenius 3.0. I’ll admit it, I just did not like the 3.0 very much. The hook and loop were not very good and the laundry tabs would not stay shut. So, our 3.0 started looking pretty beat up very quickly. My biggest complaint about it was that at about 15 months – my daughter was too big for a diaper that was supposed to last another 10-15 pounds. I am happy to say that the BumGenius 4.0 sizing is much, much better.

BumGenius 4.0 Sizing = Perfect Fit!

At 2 1/2 years, my daughter is in the 90th percentile for height and she weighs about 30 pounds. Her genes are apparently part kangaroo – since she prefers to hop, jump, skip and run rather than walk – even if it is just across the room. She has powerful little legs to go along with her battery-powered personality. This has made it tough lately to find diapers that fit her well. The BumGenius 4.0 one size we have is the new snap version and it is sized perfectly to fit her. There is still an extra snap on each side, so she can grow a bit more before the weather warms up and Mommy puts her in Potty Training Bootcamp. The rise is also much better, and she has a bit of growing room there as well.

BumGenius 4.0 Sizing For Newborns

What about smaller babies? I tried the 4.0 on my skinny newborn nephew and the fit was very good. A tad bulky, but all one size diapers have some bulk on a scrawny newborn. He was 9 pounds, but thin as you can see in the picture.
Bumgenius 40 Aio Snap Diapers


The snaps are a great improvement. Although Cottonbabies (makers of BumGenius, Flip, and Econobum) says they are using all new hook and loop that is made especially for them, I am so happy with snaps that I have not bothered to try the hook and loop.

Common Complaints?

The most common complaint about diapers wearing out is that the elastic goes bad before the diapers do. We have never personally had this problem with any of our diapers, I do hear about it from others. While some companies simply use inferior elastic, even good quality elastic can go bad prematurely. One size diapers are at particular risk since they are used for such a long period of time.

Replaceable Elastic

Clover diapers started offering replaceable elastic on their diapers several years ago and now some of the biggest names in cloth diapering are doing the same. FuzziBunz, BumGenius, and Happy Heinys one size diapers are all available with easily replaced elastic now. The BumGenius 4.0 elastic is simply tacked in at the ends, so you can clip it and thread new elastic in if needed. Replacing elastic in pocket diapers used to be a real pain and required a fairly talented seamstress. The new style BumGenius elastic is so easy to replace that even the most newly-minted seamstress could pull it off.

RWhat I Don’t Like

The one thing I still don’t like about BumGenius 4.0 one size diapers is the way the pocket opening works. The covered slit opening allows poop to get up under the flap – making it potentially really gross to get the insert out. A couple of times I have washed the diaper with the insert still in it just to get it clean enough to take the insert out before rewashing it.

Huge Selection

Oh, and did I mention the colors and prints? BumGenius 4.0 one size diapers are now available in 9 colors and 5 prints. The prints are limited edition, so there will surely be more coming at some future date.

Final Thoughts

Overall, I would recommend the BumGenius 4.0 one size diaper. I’d give it 8 stars though. If you just want a diaper you know will work, this is a good choice. It is reliable, the overall quality is great, and they are reasonably priced. The sizing is good, and you know you will be able to use it for most babies from birth to potty. I took off one star because I hate the pocket opening, and one star because they are sometimes made in Egypt.

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