Diaper Size Calculator by Weight

Find the perfect diaper size for your baby based on their weight. Works with all major brands including Pampers, Huggies, Luvs, and Honest Company.

Enter Baby's Weight

Current Weight

Complete Diaper Size Chart by Weight (2026)

This universal diaper size chart works for most major brands. Sizes may vary slightly between manufacturers, so always check the package for specific weight ranges.

Size	Weight (lbs)	Typical Age	Notes
Size Preemie	0-6 lbs	Preemie	For premature babies
Size Newborn	0-10 lbs	0-1 month	Umbilical cord cutout, extra softness
Size 1	8-14 lbs	1-4 months	Most common starter size
Size 2	12-18 lbs	3-8 months	Popular for active babies
Size 3	16-28 lbs	6-12 months	Most-used size overall
Size 4	22-37 lbs	12-24 months	Toddler transition size
Size 5	27-35 lbs	2-3 years	Active toddler fit
Size 6	35-50 lbs	3+ years	Older toddlers, overnight
Size 7	41-65 lbs	4+ years	Extended sizing

Diaper Size by Brand

While most brands follow similar sizing, there can be slight variations in fit. Here's how popular brands compare:

Pampers

Size Preemie: Up to 6 lbs
Size Newborn: Up to 10 lbs
Size 1: 8-14 lbs
Size 2: 12-18 lbs
Size 3: 16-28 lbs
Size 4: 22-37 lbs
Size 5: 27+ lbs
Size 6: 35+ lbs
Size 7: 41+ lbs

Huggies

Size Preemie: Up to 6 lbs
Size Newborn: Up to 10 lbs
Size 1: 8-14 lbs
Size 2: 12-18 lbs
Size 3: 16-28 lbs
Size 4: 22-37 lbs
Size 5: 27+ lbs
Size 6: 35+ lbs
Size 7: 41+ lbs

Luvs

Size Newborn: Up to 10 lbs
Size 1: 8-14 lbs
Size 2: 12-18 lbs
Size 3: 16-28 lbs
Size 4: 22-37 lbs
Size 5: 27+ lbs
Size 6: 35+ lbs

Honest Company

Size Newborn: Up to 10 lbs
Size 1: 8-14 lbs
Size 2: 12-18 lbs
Size 3: 16-28 lbs
Size 4: 22-37 lbs
Size 5: 27+ lbs
Size 6: 35+ lbs

Signs Your Baby Needs a Bigger Diaper Size

Time to Size Up

Red marks on thighs or waist
Frequent leaks or blowouts
Difficulty fastening the tabs
Diaper doesn't cover baby's bottom completely
Baby seems uncomfortable

Diaper Fits Well When

Waistband sits at belly button level
Two fingers fit under the waistband
Leg cuffs are pulled out and snug
No gaps around the legs
Baby can move freely

Frequently Asked Questions

When should I move up a diaper size?

Move up when your baby reaches the upper weight limit for their current size, or if you notice frequent leaks, red marks from tight elastic, or difficulty fastening tabs. It's better to size up slightly early than deal with leaks and discomfort.

Why is my baby leaking through diapers?

Leaks often indicate the diaper is too small. Other causes include: the diaper not being pulled up high enough, leg cuffs tucked in instead of out, or going too long between changes. Try sizing up first, as this is the most common fix.

Do all diaper brands fit the same?

No, fit varies by brand. Pampers tend to run slightly smaller and are good for lean babies. Huggies have a roomier fit good for chunky thighs. Honest Company diapers run true to size. Try sample packs to find the best fit for your baby's body type.

What size diapers do I need for a newborn?

Most full-term newborns start in Newborn size (up to 10 lbs) and move to Size 1 within 1-2 weeks. Babies born over 8 lbs may skip newborn size entirely. Stock up more on Size 1 than Newborn since babies grow quickly in the first month.

Should I use overnight diapers?

Overnight diapers have extra absorbency for 12+ hours of wear. Consider them once your baby sleeps longer stretches (usually 4-6 months). They typically come in sizes 3 and up. You can also size up in regular diapers for extra capacity at night.

How many diapers should I stock up on?

For newborns, expect 10-12 diaper changes per day. By 3 months, this drops to 8-10. By 6 months, about 6-8 per day. Don't stockpile too many of one size since babies grow quickly. Size 3 is the most-used size overall, so it's safe to stock up on that.