Which size fits?
- Pampers Newborn or Size 1
- Huggies Newborn or Size 1
Between sizes: Pampers suggests trying the sizes that fit and keeping the one with no leaks or marks.
Diaper size chart
| Size | Pampers | Huggies |
|---|---|---|
| Preemie | Up to 6 lb | Up to 6 lb |
| Newborn | Up to 10 lb | Up to 10 lb |
| Size 1 | 8–14 lb | 8–14 lb |
| Size 2 | 10–22 lb | 12–18 lb |
| Size 3 | 13–26 lb | 16–28 lb |
| Size 4 | 15–34 lb | 22–37 lb |
From each brand's US size chart, checked October 12, 2026: Pampers, Huggies. Ranges overlap on purpose: a baby at the top of one size fits the bottom of the next. Always follow the weight range printed on the package.
How old is a baby in each size?
It depends on birth weight and growth, so treat these as rough. For a baby born at the average weight, our growth estimate (WHO standards, via the CDC) puts each size at about:
| Size | Pampers | Huggies |
|---|---|---|
| Newborn | birth to 3 weeks | birth to 3 weeks |
| Size 1 | 3 weeks to 2 months | 3 weeks to 3 months |
| Size 2 | 2 months to 7 months | 3 months to 6 months |
| Size 3 | 7 months to 12 months | 6 months to 12 months |
| Size 4 | After 12 months | After 12 months |
For your own baby's dates, put their birth weight into the diaper calculator. It also counts how many of each size you'll use.
Signs it's time to size up
Weight is a guide, not a rule. Pampers lists these signs that a diaper is too small:
- Red marks on the thighs or waist after you take it off
- Leaks or blowouts, even when it's fastened properly
- Tabs that no longer reach the middle of the waistband
- The diaper no longer covers your baby's bottom
- You can't comfortably fit two fingers under the waistband
Source: Pampers on when to size up.
Between two sizes?
Pampers suggests trying both and keeping the one that fits without leaks or marks, and using the larger size at night if you want more room. Our calculator assumes you move up halfway through each overlap: for Pampers that's at 9 lb, 12 lb, 17.5 lb for Newborn, Size 1 and Size 2.
Before you stock up
- Buy one size ahead, not three. A pack of the next size is enough until you know when your baby will move up.
- Unopened packs can often be exchanged. Check the store's return policy before buying in bulk.
- Brands fit differently. If one leaks, the same size from another brand may not.
How many to buy of each size is worked out in the diaper calculator, and how many wipes in wipes for year one.
Recall check: on October 12, 2026 we searched new CPSC recalls since September 12, 2026 for Pampers and Huggies: none found. We check every month. How we check.
A rash that worries you, or a baby who seems uncomfortable whatever the size, is a question for your pediatrician.