Baby Tools
Diaper Size Calculator
Enter your baby's weight to find the right size, then see how long it'll last, how many to buy before sizing up, and your total cost to potty training. Works across Pampers, Huggies, Luvs, Kirkland, and more.
Find the perfect fit
What size diaper does baby need?
9 sizes available · Premium
The size and timeline update as you type. No button needed.
👶
The perfect fit awaits
Enter baby's weight to see the size, how long it lasts, and how many to buy.
Pampers Swaddlers Size Chart
Premium option
Preemie
Up to 6 lbs~12/day
Newborn
Up to 10 lbs~10/day
Size 1
8-14 lbs~10/day
Size 2
12-18 lbs~9/day
Size 3
16-28 lbs~8/day
Size 4
22-37 lbs~7/day
Size 5
27-50 lbs~6/day
Size 6
35-60 lbs~5/day
Size 7
41+ lbs~5/day
Brand Comparison
Which sizes each US brand carries
| Brand | Preemie | Newborn | S1 | S2 | S3 | S4 | S5 | S6 | S7 | S8 |
|---|---|---|---|---|---|---|---|---|---|---|
| Pampers Swaddlers | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | - |
| Pampers Baby Dry | - | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
| Pampers Cruisers 360 | - | - | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | - |
| Huggies Little Snugglers | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | - | - |
| Huggies Little Movers | - | - | - | - | ✓ | ✓ | ✓ | ✓ | ✓ | - |
| Luvs | - | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | - | - |
| Kirkland Signature (Costco) | - | - | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | - | - |
| Up & Up (Target) | - | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | - |
| Parent's Choice (Walmart) | - | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | - |
| Honest Company | - | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | - | - |
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From first kicks to first steps, capture and share your family's precious moments in one beautiful timeline.
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Common Questions
- How do I know when to go up a diaper size?
- Signs include frequent leaks or blowouts, red marks on your baby's thighs or waist from tight elastic, difficulty fastening the tabs comfortably, and the diaper looking overly stretched. Move up a size based on fit, not just the weight range on the package.
- What diaper size does a newborn need?
- Most newborns start in newborn size (up to 10 lbs) or size 1 (8-14 lbs). Babies born over 9 pounds may skip newborn size entirely. Don't stock up on newborn diapers, since most babies move to size 1 within 2-4 weeks.
- How many diapers does a baby use per day?
- Newborns use 10-12 diapers per day. This drops to about 8-10 per day by 3 months, and 6-8 per day by 6 months. The total in the first year is roughly 2,500-3,000 diapers, with the highest usage in the first 3 months.
- What size diaper does my baby need by weight?
- Diaper sizes are set by weight, not age: Newborn fits up to 10 lbs, Size 1 is 8-14 lbs, Size 2 is 12-18 lbs, Size 3 is 16-28 lbs, Size 4 is 22-37 lbs, Size 5 is 27+ lbs, and Size 6 is 35+ lbs. Because the ranges overlap, weigh your baby and pick the size where they sit comfortably in the middle of the range.
- What Pampers or Huggies size does my baby need?
- Pampers and Huggies use the same numbered sizing, but the weight ranges differ slightly by brand and product line, and the fit varies: Pampers tends to run a little trimmer while Huggies is cut wider. Enter your baby's weight and brand above to see the exact recommended size, and size up if you're seeing leaks or red marks.
- How long does a baby stay in each diaper size?
- It depends on growth rate, but a rough guide: Newborn lasts only 2-4 weeks (heavier babies skip it), Size 1 about 6-10 weeks, Size 2 around 2-3 months, and Size 3 the longest, often 4-6 months as growth slows. The calculator above estimates the weeks left in your baby's current size from their weight using typical WHO growth rates, so you can buy just enough before sizing up.
- How many diapers will my baby use before potty training?
- Most children use roughly 6,000-7,000 diapers from birth until they're out of diapers around age 3. At about $0.30 each (the AAP's estimate), that's $2,000 or more. Usage starts high at 10-12 a day as a newborn and tapers to 5-6 a day as a toddler. Enter your baby's weight above to estimate how many, and how much, you have left from here.
For educational purposes only, not a substitute for professional medical advice. Always consult your pediatrician with questions about your child's health.