Diaper Size Comparison Between Brands: Cross-Brand Chart

AvatarBySaima Mostari

No, a size 3 is not the same diaper in every brand. Across seven US brands whose own size charts we read on August 29, 2026, the published size 3 band starts somewhere between 13 lb and 16 lb and ends somewhere between 21 lb and 28 lb. At 15 lb, three of those charts allow only a size 2, three accept a 2 or a 3, and Pampers’ own bands accept a 2, a 3 or a 4. So when you change brands, start at the same number, then judge the fit on your baby rather than on the box.

Diaper Size Comparison Between Brands, Cross-Brand Chart

“I used to assume the same diaper size meant roughly the same fit across brands, but switching brands taught me how unreliable that assumption can be. I’ve had the same size number fit comfortably in one diaper and feel noticeably different in another, even without my child’s weight changing much. Now I use the new brand’s weight range only as a starting point, buy the smallest pack first, and judge the actual fit around the waist and thighs before committing to a full box.”

The cross-brand diaper size chart

Every range below was copied from that brand’s own published chart on August 29, 2026. Brands revise these pages, so the number printed on the pack in your hand wins if it differs from what you see here.

Size Pampers Honest up & up (Target) Coterie Millie Moon Rascals Seventh Generation
Newborn under 10 lb up to 10 lb under 10 lb under 10 lb under 9 lb 2 to 9 lb up to 10 lb
1 8 to 14 lb 8 to 14 lb 8 to 14 lb 8 to 12 lb 6 to 11 lb 6 to 11 lb 8 to 14 lb
2 10 to 22 lb 12 to 18 lb 12 to 18 lb 10 to 16 lb 9 to 18 lb 9 to 18 lb 12 to 18 lb
3 13 to 26 lb 16 to 28 lb 16 to 28 lb 14 to 24 lb 13 to 24 lb 13 to 24 lb 16 to 21 lb
4 15 to 34 lb 22 to 37 lb 22 to 37 lb 20 to 32 lb 22 to 33 lb 22 to 33 lb 20 to 32 lb
5 20 to 37 lb 27+ lb 27+ lb 27+ lb 28 to 39 lb 28 to 39 lb 27 to 35 lb
6 23 to 44 lb 35+ lb 35+ lb 35+ lb 33 to 44 lb 33 to 44 lb over 35 lb
7 26 to 50 lb 41+ lb 41+ lb 41+ lb 37+ lb 37+ lb not listed
8 30+ lb not listed 46+ lb not listed not listed not listed not listed

Two things will not fit in a cell. Pampers also publishes a preemie size at under 6 lb, and Coterie publishes an “N+1” alongside its newborn size, also at under 10 lb.

Where each range came from, all read August 29, 2026:

Why Huggies, Kirkland, Luvs and Hello Bello are not in it

They are missing for one reason: on the date above we could not read a current published weight chart on the brand’s own page. The Huggies size pages and the Costco listing for Kirkland Signature both refused the request. Luvs and Hello Bello point to sizing help without showing a band we could quote.

We could have filled those columns from a comparison blog or a third-party listing. That is how a wrong number spreads, because those pages copy each other and nobody re-checks when a brand revises a band. Four brands you can verify beat eight where half are guesses. If you need one of the missing four, the pack itself and that brand’s own site are the two places worth trusting.

Where the charts agree and where they part company

They agree at the newborn end. Five of the seven stop newborn size at 10 lb, and five start size 1 at 8 lb. If your baby is around 9 or 10 lb, almost every brand puts you in the same place.

They part company from size 2 onward. Look along the size 3 row. Seventh Generation runs it from 16 to 21 lb, a 5 lb window. Honest and up & up run the same number from 16 to 28 lb, a 12 lb window. Pampers starts it at 13 lb. That is a 3 lb difference in where the size begins and a 7 lb difference in where it ends, on the same printed number.

Size 4 is where the floors spread widest. Pampers opens size 4 at 15 lb. Honest, up & up, Millie Moon and Rascals open theirs at 22 lb. A baby can be a comfortable size 4 in one brand and two sizes away from it in another.

One published number to treat with care. Pampers lists size 8 at 30+ lb, which sits below the floor of its own size 7 band. We are reporting the chart as published rather than tidying it up. On the shelf, go by the range printed on the pack.

The same baby, three weights, seven brands

This is the table nobody prints, and it is only arithmetic on the bands above. It shows every size number whose published range would accept that baby.

If your baby weighs Pampers Honest up & up Coterie Millie Moon Rascals Seventh Generation
15 lb 2, 3 or 4 2 2 2 or 3 2 or 3 2 or 3 2
20 lb 2, 3, 4 or 5 3 3 3 or 4 3 3 3 or 4
26 lb 3, 4, 5 or 6 3 or 4 3 or 4 4 4 4 4

Read the 26 lb row slowly. Honest and up & up still call that baby a size 3. Coterie, Millie Moon, Rascals and Seventh Generation have already moved them to a 4. Both are correct according to the makers, which tells you the number on the box is a label for a weight band, not a measurement of your baby.

It also says something specific about Pampers. Its bands are wide and heavily overlapped, so at most weights its chart will accept three or four different sizes. That is not a flaw, it is a design choice, and it means the chart hands the decision back to you sooner than the narrower charts do. The diaper fit troubleshooting guide covers what to do with a decision the chart will not make for you.

Who publishes the big sizes

If you are past size 6 the comparison narrows fast, because not every brand goes there.

Of the seven charts read here, six publish a size 7 and only two publish a size 8: Pampers at 30+ lb and up & up at 46+ lb. Seventh Generation’s chart stops at size 6. Millie Moon and Rascals open size 7 at 37 lb, while Honest, up & up and Coterie open theirs at 41 lb.

So a toddler who has outgrown size 6 has fewer real options than the shelf suggests, and the first question is which brands still make the size, not which brand fits best.

Switching brands without a leak week

The switch itself is simple, and the mistake people make is buying the box first.

  1. Start at the same size number. Across the charts above, a given weight usually lands on the same number or one adjacent to it. Same number is the right opening guess.
  2. Look your baby’s weight up in the new brand’s own band before you buy. If they are within a pound or two of the top of that band, the next size up is the better opening guess, because babies gain during the pack, not after it.
  3. Buy the smallest pack the brand sells. A jumbo box commits you to a cut you have not yet seen on your baby.
  4. Give it two days, then judge the fit rather than the number. Red marks at the waist or thighs, tabs pulled toward the center to meet, and a waistband riding below the belly button are the signals worth watching. The four signs a diaper is too small walks through each one, including the one most parents miss.

If the new brand leaks at the same size that worked before, the size is usually not the problem. Cut is. A brand with a narrower cut can leak at the legs on a baby whose thighs a wider brand handled comfortably, at exactly the same weight.

Why the ranges overlap in the first place

Every chart in the table overlaps itself. Pampers size 2 ends at 22 lb while size 3 starts at 13 lb. Coterie size 3 ends at 24 lb while size 4 starts at 20 lb.

The reason is plain once you see it. A weight band is drawn around a spread of babies, not around one body. Two babies at 20 lb can differ by inches at the waist and the thigh, so the maker publishes a band wide enough to include both and lets fit settle the rest. The overlap is the maker admitting that weight alone does not finish the job.

Which is why the practical answer to “what size is my baby in this brand” is a range, and the tie-breaker is always the fit on the child in front of you.

What a diaper size comparison between brands cannot tell you

Weight is the only number these brands publish in common. Rise, leg opening and waistband stretch are the differences parents actually feel, and none of the seven charts prints them as measurements, so this page does not print a cross-brand shape ranking it cannot source. Anyone who hands you a confident one is estimating.

That is the honest limit of a comparison like this. The table narrows the field to a size or two. Your baby settles it.

Fit, skin and when the pediatrician is the right call

A diaper that fits badly is not only a laundry problem. The American Academy of Pediatrics, on its HealthyChildren.org page about diaper rash, notes that “the diaper area spends much of the day in contact with two very irritating substances: urine and stool,” and advises to “change diapers frequently,” adding that “moisture from leaving a wet or soiled diaper on too long can cause skin to chafe.” On fit specifically, the same page says to “make sure the diaper isn’t too tight, especially overnight,” and notes that “a diaper that is loose will be less likely to rub against the skin.”

The AAP also gives clear escalation points on that page: contact your child’s doctor if a rash does not clear after two to three days of simple care, if it includes pimples, blisters or oozing sores, or if your baby has a fever along with the rash.

None of this page is medical advice, and no diaper on it is described as preventing or treating anything. If your baby’s skin is broken, painful or not settling, your pediatrician is the person to ask, and their scale is also the most reliable place to get the weight you have been typing into these charts.

FAQ

Is a Pampers size 3 the same as a Honest size 3?
No. Read on their own charts on August 29, 2026, Pampers publishes size 3 as 13 to 26 lb and Honest publishes it as 16 to 28 lb. A 14 lb baby is inside the Pampers band and below the Honest one.

Should I size up when I switch brands?
Not automatically. Start at the same number unless your baby is within a pound or two of the top of the new brand’s published band for that size, then let the fit decide over the next couple of days.

Which brand covers the widest weight range at each size?
Of the seven read here, Pampers publishes the widest bands, for example 10 to 22 lb at size 2 and 15 to 34 lb at size 4. Seventh Generation publishes the narrowest size 3, at 16 to 21 lb.

Are newborn sizes the same across brands?
Close, but not identical. Five of the seven cap newborn size at 10 lb, Millie Moon caps it under 9 lb, and Rascals publishes a 2 to 9 lb range. Pampers also publishes a separate preemie size at under 6 lb.

Do store brands use the same bands as the national brands?
Sometimes the numbers match exactly. up & up publishes the same bands as Honest from size 1 through size 7. Matching bands do not mean a matching cut, which is why the small pack comes before the box.

Freshness

Brand size charts change without notice. Every range on this page was read from the brand’s own page on August 29, 2026, and this page is re-checked at least quarterly, or sooner if a reader tells us a band has moved.

Author Profile

Saima Mostari
Saima Mostari
Saima Mostari is the founder and author of BelovedTots. She has raised two young children, Pona and Ruku, and spent years working in child development at Neurosparks, a therapy center that provides Speech Therapy, Occupational Therapy, and ABA Therapy for children with developmental needs.

It was there, watching long therapy sessions get interrupted by leaking, ill-fitting diapers, that she began researching which products actually perform under real-world conditions, not just on the packaging.

She holds a Master's in Psychology and Guidance from the University of Dhaka, and brings a behavioral observation lens to every product she reviews. When she's not testing diapers or writing guides, she's probably negotiating bedtime with a 4-year-old.