A diaper size guide is a weight-based reference chart that helps parents find the right diaper size from Preemie through Size 7, with weight ranges, typical age estimates, daily diaper counts, and fit tips.
Diaper Size Guide
Enter your baby's weight to find the right diaper size, or browse the full size chart below.
Full Size Chart
| Size | Weight | Age |
|---|---|---|
| Preemie | 0-6 lbs | Premature babies |
| Newborn | 0-10 lbs | 0-1 month |
| Size 1 | 8-14 lbs | 0-4 months |
| Size 2 | 12-18 lbs | 2-6 months |
| Size 3 | 16-28 lbs | 5-15 months |
| Size 4 | 22-37 lbs | 12-24 months |
| Size 5 | 27-45 lbs | 18-36+ months |
| Size 6 | 35-50 lbs | 3+ years |
| Size 7 | 41-65 lbs | 3-4+ years |
Diaper Fit Tips
- The waistband should fit snugly but allow two fingers between the diaper and baby's belly.
- Leg cuffs should be pulled out (not tucked in) to prevent leaks.
- If you see red marks on baby's thighs or waist, it's time to size up.
- Frequent blowouts usually mean it's time for the next size, not a tighter fit.
- If the diaper looks saggy or droopy, you may have sized up too soon.
- Overnight diapers are one size up from daytime — extra absorbency for longer stretches.
Sources
Diaper Size Chart by Weight
Size: Preemie
Weight (lbs): Up to 6
Age Range: Premature babies
Diapers/Day: 8-12
Notes: Designed for premature or very small newborns. Extra soft with umbilical cord cutout.
Size: Newborn
Weight (lbs): Up to 10
Age Range: 0-1 month
Diapers/Day: 8-12
Notes: Umbilical cord notch in most brands. Expect to go through these quickly — most babies move to Size 1 within 2-4 weeks.
Size: Size 1
Weight (lbs): 8 - 14
Age Range: 0-4 months
Diapers/Day: 8-10
Notes: First size most babies spend significant time in. Wetness indicator is helpful at this stage.
Size: Size 2
Weight (lbs): 12 - 18
Age Range: 2-6 months
Diapers/Day: 8-10
Notes: Baby is becoming more active. Look for stretch panels for comfort during movement.
Size: Size 3
Weight (lbs): 16 - 28
Age Range: 5-15 months
Diapers/Day: 6-8
Notes: Most popular size — babies spend the most time in Size 3. Consider overnight diapers if leaking at night.
Size: Size 4
Weight (lbs): 22 - 37
Age Range: 12-24 months
Diapers/Day: 6-8
Notes: Toddlers need more absorbent diapers for larger voids. Look for brands with extra absorbency zones.
Size: Size 5
Weight (lbs): 27 - 45
Age Range: 18-36+ months
Diapers/Day: 5-7
Notes: Often the transition size before potty training. Many brands offer pull-up style for this size.
Size: Size 6
Weight (lbs): 35 - 50
Age Range: 3+ years
Diapers/Day: 4-6
Notes: For larger toddlers still in diapers. Pull-up training pants are a popular alternative at this size.
Size: Size 7
Weight (lbs): 41 - 65
Age Range: 3-4+ years
Diapers/Day: 4-6
Notes: Largest disposable diaper size. Not all brands make this size — check Pampers or specialty brands.
| Size | Weight (lbs) | Age Range | Diapers/Day | Notes |
|---|---|---|---|---|
| Preemie | Up to 6 | Premature babies | 8-12 | Designed for premature or very small newborns. Extra soft with umbilical cord cutout. |
| Newborn | Up to 10 | 0-1 month | 8-12 | Umbilical cord notch in most brands. Expect to go through these quickly — most babies move to Size 1 within 2-4 weeks. |
| Size 1 | 8 - 14 | 0-4 months | 8-10 | First size most babies spend significant time in. Wetness indicator is helpful at this stage. |
| Size 2 | 12 - 18 | 2-6 months | 8-10 | Baby is becoming more active. Look for stretch panels for comfort during movement. |
| Size 3 | 16 - 28 | 5-15 months | 6-8 | Most popular size — babies spend the most time in Size 3. Consider overnight diapers if leaking at night. |
| Size 4 | 22 - 37 | 12-24 months | 6-8 | Toddlers need more absorbent diapers for larger voids. Look for brands with extra absorbency zones. |
| Size 5 | 27 - 45 | 18-36+ months | 5-7 | Often the transition size before potty training. Many brands offer pull-up style for this size. |
| Size 6 | 35 - 50 | 3+ years | 4-6 | For larger toddlers still in diapers. Pull-up training pants are a popular alternative at this size. |
| Size 7 | 41 - 65 | 3-4+ years | 4-6 | Largest disposable diaper size. Not all brands make this size — check Pampers or specialty brands. |
Sizes may vary slightly between brands. Weight is the primary factor in choosing diaper size.