The Guide to Nappy Sizes 2025: Enhanced Edition

Choosing the right nappy for your baby is essential for their comfort, health, and your peace of mind. While age can be a general indicator, weight – whether you use kilograms (kg) or pounds (lbs) – is the most accurate way to determine the correct nappy size. This guide provides a comprehensive overview of nappy sizing in Australia, including fit checks, practical tips, and additional considerations for a perfect fit.

Official Nappy Size Chart (Australian Market)

Based on common Australian nappy brands, here's a general overview of nappy sizes:

Tip: Always check the specific brand’s size chart, as slight variations may exist.

Find the Best Fit

• Weight Over Age: Babies grow at different rates, so always prioritize weight over age recommendations.
• Brand Variations: Different brands (e.g., Aiwibi vs. Pampers) may have slightly different sizing. Always check the packaging for the specific brand's weight guidelines.
• Nappy Pants vs. Regular Nappies:
  • Nappy pants are ideal for active babies (usually starting at Size 3 or Size 4) as they offer more flexibility and ease of movement.
  • Some brands offer overnight nappies with extra absorbency (same sizing as regular nappies) designed to handle longer wear and heavier wetting.

Nappy Pants vs. Tape Nappies

When to switch? Once the baby starts rolling/crawling (~6 months+).

• Fit Check Indicators:
  • Should sit below the belly button.
  • Snug but not tight—two fingers should fit comfortably under the waistband and leg cuffs.
  • No red marks should be visible on the baby's waist or thighs after removing the nappy.
  • No leaks should occur regularly around the legs or waist.
• Baby’s Shape & Activity Level:
  • Longer, leaner babies might fit better in a nappy with a narrower cut, while shorter, chunkier babies may need a brand with a wider fit or elasticated waistband to accommodate their thigh circumference comfortably without causing red marks.
  • If your baby is crawling/walking, consider nappy pants for easier movement and changes.

Understand the Nappy Size Chart

1. Weigh your baby: Use a reliable baby scale to get an accurate weight.
2. Locate the weight range: Find the size in the chart that corresponds to your baby's current weight.
3. Consider brand specifics: If you have a preferred brand, always consult their specific size chart on the packaging or website, as there can be slight variations between brands.

   Aiwibi nappy sizes chart

   
4. Factor in your baby's build: If your baby has a unique body shape (e.g., very chunky thighs), you might need to consider a size up or a brand known for a more accommodating fit. Look for nappies with features like an elasticated waistband and leg cuffs.
5. Observe the fit: After putting on a new nappy, check the fit indicators mentioned above to ensure it's snug but not too tight and provides adequate coverage.

Newborn Diaper Specifics (0-5 kg / Up to 11 lbs)

Newborn nappies (Size 1) are designed with the unique needs of a newborn in mind:

• Umbilical Cord Notch: Many newborn nappies feature a cutout or a fold-down section at the front to avoid irritating the baby's healing umbilical cord stump.
• Extra Softness: Newborn skin is very delicate, so these nappies are typically made with extra soft and gentle materials.
• High Absorbency: Despite their small size, newborn nappies are designed to handle the frequent but smaller voids of newborns.
• Wetness Indicator: Some newborn nappies have a wetness indicator, a line that changes color when wet, helping new parents know when it's time for a change without having to constantly check.

Signs to Size Up

It's time to move to the next nappy size when you notice any of the following:

• Frequent Leaks: If the nappy is consistently leaking, especially during the day, it might not be absorbent enough for the increasing volume of urine, or it might be too small to contain it properly.
• Red Marks: Red marks around your baby's waist or thighs indicate that the nappy is too tight and digging into their skin.
• Poor Fit: The nappy looks or feels too snug, the fastening tabs are hard to reach or don't close comfortably, or the nappy doesn't fully cover your baby's bottom.
• Tabs Don't Meet: If the fastening tabs are being stretched to meet in the middle, it's a clear sign the nappy is too small.
• Increased Frequency of Blowouts: While occasional blowouts happen, more frequent occurrences can mean the nappy isn't large enough to contain the waste.
• Discomfort: Your baby seems uncomfortable or is fussier during nappy changes, possibly due to a too-tight nappy.
• The nappy is constantly saturated: If you find the nappy is completely soaked through shortly after putting it on, the next size up will offer more absorbency.

Proper Diaper Fit Guidelines

Ensuring a proper nappy fit is crucial for comfort and preventing leaks:

1. Positioning: Place the nappy evenly under your baby, with the back waistband at their natural waistline (usually just below the belly button).
2. Fastening: Bring the front of the nappy up between your baby's legs and fasten the tabs securely on the front panel. The tabs should be symmetrical.
3. Snugness: The nappy should be snug but allow for movement. You should be able to slide two fingers comfortably under the waistband and leg cuffs.
4. Leg Cuffs: Ensure the leg cuffs are pulled out and not tucked in to prevent leaks around the legs.
5. Coverage: The nappy should fully cover your baby's bottom without any gaps.
6. Waistband: The waistband should sit comfortably and not be folded down.

Nappy Usage Scenarios

• Nighttime Nappy Solutions for Leak-Free Sleep

  For better overnight protection:

  • Choose overnight-specific nappies like Aiwibi Ultimate Comfort Night Nappy Pants - designed for 12-hour dryness with extra absorbent cores
  • Size up strategically (e.g., move to Size 5 if daytime wear is Size 4) for increased capacity
  • Double protection with a bamboo nappy liner for heavy wetters
  • For active toddlers: Nappy pants provide mobility, but traditional overnight nappies typically offer superior absorbency
• Leaks: Persistent leaks indicate either an incorrect size or insufficient absorbency. Ensure the leg cuffs are properly positioned. If sizing up doesn't help, try a different brand or a nappy with higher absorbency.
• Nappy Rash: To minimize nappy rash, change wet or soiled nappies frequently. Ensure the nappy area is clean and dry before putting on a new nappy. Consider using barrier creams to protect the skin. If your baby experiences looser stools due to teething, more frequent changes are essential. Look for wipes that are fragrance-free and alcohol-free to avoid irritation. Allowing for some nappy-free time each day can also help.

Aiwibi Nappy Subscription Services in Australia

Save time and money with auto-delivery options:

• Subscribe & Save for 10% off. Choose delivery frequency (currently every 2 weeks).
• Subscribe & Save for 8% off. Choose delivery frequency (currently every 3 weeks).
• Subscribe & Save for 5% off. Choose delivery frequency (currently every 4 weeks).

Other activities: 5% off your first order! Learn more about Aiwibi!

FAQs

• Q: What age wears Size 4 nappies?
  • A: Typically 12-24 months, but always check weight (9-14 kg / 20-31 lbs).
• Q: How much is 14 lbs in kg?
  • A: 14 lbs ≈ 6.35 kg (fits Size 2 or small Size 3, depending on brand).
    
• Q: How to prevent nappy rash while teething?
  • A: Teething can cause looser stools—change nappies frequently and use barrier creams at each change to protect the skin from increased moisture and irritation. Ensure the nappy area is thoroughly cleaned and dried during each change.

By following this comprehensive guide, you can confidently choose the perfect nappy size and type to keep your little one comfortable, dry, and happy!