Finding the Right Fit for Your Baby
Every baby grows at their own pace, and finding the right nappy size makes all the difference. Our sizing guide is designed to help you choose a comfortable, secure fit that supports movement, prevents leaks, and keeps your baby feeling happy and dry.
Use our guide as a starting point, and size up when needed to ensure the best comfort as your baby grows.
Nappy Size Chart
Size
lbs
kgs
N
< 9 lbs
< 4 kg
1
6 – 11 lbs
3 – 5 kg
2
9 – 18 lbs
9 – 18 lbs
3
13 – 24 lbs
6 – 11 kg
4
22 – 33 lbs
10 – 15 kg
5
28 – 39 lbs
13 – 18 kg
6
33 – 44 lbs
15 – 20 kg
7
37+ lbs
17+ kg
Helpful tip: If your baby’s weight falls between two sizes, we recommend choosing the smaller size. Koala Hug nappies are designed with a slightly roomier fit to provide extra comfort without compromising protection.
Training Pants Size Chart
Size
lbs
kgs
2T / 3T
22 – 33 lbs
10 – 15 kg
3T / 4TM
28 – 39 lbs
13 – 18 kg
4T / 5T
33 – 44 lbs
15 – 20 kg
5T / 6T
38+ lbs
17+ kg
Helpful tip: If your baby’s weight falls between two sizes, we recommend choosing the smaller size. Koala Hug nappies are designed with a slightly roomier fit to provide extra comfort without compromising protection.
Finding the Best Nappy Fit for Your Baby
Choosing the right nappy size plays a big role in keeping your baby comfortable, dry, and happy. This guide is here to help you understand fit, sizing, and when it might be time to make a change — without the guesswork.
1. What does a well-fitting nappy look and feel like?
A good-fitting nappy should sit comfortably around your baby’s waist and legs without feeling tight. You should be able to move a finger easily under the waistband. If you notice deep red marks, frequent leaks, or restricted movement, the fit may need adjusting.
2. How do I know when it’s time to change nappy sizes?
Babies grow quickly, and signs like repeated leaks, tight fastening tabs, or reduced coverage often mean it’s time to move up a size. Growth spurts can happen suddenly, so checking fit regularly helps maintain comfort and protection.
3. Is it possible for a nappy to be too large?
Yes. A nappy that’s too big may not seal properly around the legs or waist, leading to leaks. The right size should feel secure and supportive without sagging, helping keep messes contained and your baby comfortable.
4. What should I use to choose a size — age or weight?
Weight is the most reliable way to choose the correct nappy size. Babies develop differently, so age can vary widely. Our Koala Hug sizing guide is based on weight ranges to help you find the best fit for your baby’s body.
5. My baby has a round tummy or chubby thighs — should I size up?
Not always. Koala Hug nappies are designed with soft, stretchy materials that adapt to different shapes. If the nappy isn’t digging in and there are no leaks, the size is likely suitable. Comfort and fit matter more than appearance alone.
6. When should I consider switching from nappies to training pants?
Nappies are ideal for everyday wear and younger babies, while training pants are better suited for toddlers beginning toilet training. If your child is showing interest in independence or using the potty, training pants may be the next step.
Koala Hug Sizing Tip
If your baby’s weight sits between two sizes, we recommend choosing the smaller size. Koala Hug nappies are designed with a slightly roomier fit to provide comfort and flexibility while still offering reliable leak protection.