What Age Should a Child Start Wearing Underwear? A Parent’s Guide

The best age for a child to start wearing underwear depends on readiness, not just age—typically between 3 and 5 years old. Key signs include recognizing when they need to go, staying dry longer, or asking for “big kid” underwear. Make the switch exciting by letting them pick their favorite characters and celebrating small wins. Remember, setbacks happen, but with patience and the right approach, your toddler will master this milestone!

Kids moving on from diapers to underwear go through significant development. But it’s up to the parents to know at what age a child should start wearing underwear. The age typically is between three and five years old, but that number can change depending on the child’s mental and physical development.

Only by looking at the signs and comparing them with the typical age will parents know for sure. To help with the transition, I have shared my guide and will also share how you can find the right underwear for children to wear. Parents will have challenges to overcome and special considerations to consider. But let’s follow a calm and patient attitude so parents like you can easily cover this milestone.

When Should a Child Start Wearing Underwear?

To find out the best age for a child to start wearing underwear, parents need to look for certain signs. While it’s true that kids as young as 2 can wear underwear, this isn’t always the case, which is why the signs are important. They indicate whether or not a child is ready to wear underwear consistently.

Signs Your Child Is Ready for Underwear

The signs will be physical readiness, while behavioral and emotional signs are also important and need to be considered. Together, these signs will signal to parents that they should introduce underwear to their children.

Physical Readiness

The main physical sign that parents need to look for is how long their child can stay dry. Ideally, parents should wait for their child to be able to stay dry for over two hours regularly before they introduce underwear. The period will tell parents that their child has better bladder control.

The next physical sign that parents should look for is the child indicating they need to go to the bathroom independently. When kids can do so on their own, it shows parents that their child understands the signs from their body and is aware of what they mean.  

Cognitive and Emotional Readiness

The child must also show signs of cognitive and emotional maturity along with the physical. Cognitive maturity means the child can follow simple instructions, such as when and where to go to the potty. Being able to do so means that the child can follow instructions and knows doing so is important or helpful.

Emotional maturity means the child is asking about underwear, what it is, why adults or other kids wear it, and wanting to do the same. This interest means that it’s time to introduce underwear to the child and have them start wearing it.

Behavioral Cues

Finally, kids also need to show behavioural signs that they are ready to wear underwear. One behavioral cue is that the child can sit on the potty on their own until they are done without input from parents. This willingness means they know they should be sitting down.

Another cue is not wanting to wear dirty diapers for too long or asking parents to change them immediately after pooping. This cue means they don’t like the feeling, and wearing underwear will ensure they don’t have to.

These simple signs are important, and parents need to be on the lookout for them if they want to transition their child from diapers to underwear. There are other signs like the ones I mentioned that parents should recognize independently.

Average Age for Transitioning to Underwear

Aside from looking for certain signs, parents can also use their kids’ age as a factor in determining whether their child should start wearing underwear. But then the question is, at what age should a child start wearing underwear?

General Age Range (3-5 Years Old)

The simple answer is between three and five is the right time to start. At this age, a child has a good enough understanding to follow instructions and is physically and emotionally mature. However, parents also need to know that not all kids follow this pattern, so they should look for the signs.

If a child isn’t ready, don’t attempt to make them wear underwear. In most cases, parents will be unsuccessful and will have to deal with a lot of tantrums and crying. Attempting and failing will also lead to the child pushing off underwear for longer.

Boys vs. Girls – Is There a Difference?

Some parents believe that girls mature faster than boys, which is why they have their daughters wear underwear earlier. This is true in some cases, but there is no fact or proof, so don’t believe it too much.

Some believe that girls can complete their potty training earlier than boys. They say that girls can complete their training in less than three years, whereas boys might need up to 3.5 years. While some studies have given similar results, they aren’t definitive. Kids develop at their own pace, which sometimes follows their studies. There is a difference, and it all depends on how a child develops.

Late Bloomers – When to Seek Advice

While I do keep saying children develop differently, there comes a time when parents might want to consult with a specialist. If a child shows no desire to wear underwear and has trouble knowing when to go to the toilet after the age of four or five, then a consult might be necessary.

I recommend visiting a pediatrician to see if there is a medical reason behind it. If there isn’t, then parents might have to visit a child psychologist. It might just be that the child is developing slower than normal, but I believe in being safer than sorry later on.

How to Transition from Diapers to Underwear

With a clearer understanding of at what age a child should start wearing underwear, parents should now learn how to transition them into it. My guide will also lay down the simple steps to follow along with how to pick the right one for the child.

Step-by-Step Guide for Parents

This guide will help parents introduce underwear to kids and ensure their comfort when wearing it for a long time.

Introducing the Concept of Underwear

When you introduce children to underwear during or after potty training, you need to make sure they understand what it is. Have the kids look at underwear and adults or older siblings wearing it to get more comfortable with it. To make the transition easier, parents can also make their children pick the one they like to build more excitement and willingness.

Reading books and watching videos about underwear with your children can also help with the transition and introduction. These books and videos make it easier for kids to learn about underwear and normalize it for them.

Daytime vs. Nighttime Training

Parents will learn to split the training between night and day during the underwear transition and potty training. Daytime training will come first because parents can observe their children’s behavior and help them more easily if they are uncomfortable. Also, if there is a mess, parents can clean it up more easily in the day compared to at night.

Once the children are more used to wearing underwear and have better potty training, nighttime training can start. To ensure kids don’t make a mess on the bed, parents should encourage the kids to go to the potty before sleeping and wear pull-ups or training underwear. I also suggest parents put waterproof covers on the bed, just in case.

Potty Training and Underwear: A Combined Approach

They started to wear underwear and, using the potty, go hand in hand with kids everywhere. There is a reason for it. The better a kid is on the potty, the more willing they will be to wear underwear. Therefore, parents should use a combined approach with underwear and potty training for more success.

To ensure this success, I recommend a reward approach. In this approach, parents reward the child every time a child uses the potty successfully or doesn’t wet themselves. The reward can be a sticker or just some positive encouragement. Either will work to motivate the child more and make them happy.

This doesn’t mean parents can punish the child if they make a mistake; that’s completely forbidden. Be patient and calm, help the child know it’s okay, and allow them more time and encouragement to do better.  

Choosing the Right Underwear for Your Child

When children start wearing underwear, they can’t wear the ones adults or older kids wear. They need underwear that is comfortable and made from softer materials. So, parents need to find the right underwear for their child to make the transition smooth and fuss-free.

Fabric and Comfort Considerations

Because underwear needs to be super comfortable for a child to wear, parents need to consider the fabric. Not all fabrics are ideal for children, and some kids are often allergic to some. I suggest only buying 100% cotton child underwear because it is more breathable and reduces the chances of irritation.

Cotton is also hypoallergenic, so parents don’t need to worry about allergies with this underwear. If possible, also look for underwear made from a blend that has moisture-wicking features. This will enhance your child’s comfort and fit.

Fun Designs to Encourage Compliance

Unlike underwear for adults, which comes in bland colors and usually has no designs, children’s underwear comes in fun colors and patterns. The colors and designs make them more likable to kids and motivate them to wear them often. When parents have their kids pick one to wear, children will do so if they see colorful and fun-looking ones.

Training underwear works like diapers by preventing leaks when children have accidents. When children start wearing underwear at a young age, the training ones help them get used to them, so they prefer them more.  

Sizing and Fit Guide

Picking the right fit for underwear means parents must find snug, not tight, ones to stay comfortable. At the same time, parents must pick ones that aren’t too loose to ensure they don’t feel like diapers to children. If it does, then the transition will happen more slowly.

Related: What size is 150 in children’s clothes?

Common Challenges and Solutions

Like most processes for children, this also comes with challenges that parents need to solve to complete. When children start wearing underwear at a young age, they will resist it out of fear and not being familiar with it.

Resistance to Wearing Underwear

The main reason for resisting underwear is because children are afraid of accidents or their preference for diapers.

Fear of Accidents

First, parents need to tell their kids that the fear of causing accidents is completely normal. They also need to tell them they won’t be upset or angry if it happens. Reassuring them and continuing to give positive reinforcement is the key to helping children overcome their fear.

Preference for Diapers or Pull-Ups

The best way to help break a child’s preference for diapers or pull-ups is to switch to underwear when they play. The games will distract them from wearing underwear. As days go by, extend the time they wear the underwear. This gradual approach worked quite well for me and will also work for other parents.

Frequent Accidents After Switching

Kids’ fear of accidents after switching to underwear is valid, but there are ways to reduce the chances.

Is This Normal?

Yes, kids will have accidents during the transition to underwear, more in some cases but that’s completely normal. This will continue for a few weeks or even a month or two for some kids.

How to Reduce Accidents

The best way to reduce the chances of these accidents for kids is to increase the frequency of potty breaks. When a child starts wearing underwear for the first time, parents should have their child visit the potty once every 1.5 to 2 hours. They should also limit any sugary treats a child eats, as that just increases the urges.

Regression After Starting Underwear

The possibility of a child regressing back to diapers after starting to wear underwear is not common, but it’s not rare, either. There are reasons for the regression, but they can be handled.

Possible Causes (Stress, Changes, etc.)

In most cases, a child regresses back to diapers because of some external factor like stress or changes to their environment. I have heard that if a child sees another child near them, a sibling, they will fight back with their parents and want to wear diapers again. The setback is uncommon but normal, and parents shouldn’t stress too much.

How to Handle Regression Gently

The best way to handle this regression is for the parents to calm down and examine the situation. Rather than fighting back, the parents should allow the child to wear their training underwear, which is similar to diapers. Then, after a few days, they should gradually revert to regular underwear. Doing it slowly will ensure that a child won’t notice the change.

Special Considerations

In certain cases, a child is born with special needs, and when this child starts wearing underwear, they need some special consideration.

Underwear for Children with Special Needs

Usually, the considerations are related to the child’s senses; thus, they require adaptive underwear.

Sensory Issues and Solutions

Some children are more touch-sensitive than others. The more sensitive ones will need to wear seamless and tagless underwear, which are made to be less irritating to the touch.

Adaptive Underwear Options

Children who have problems with movement need to wear adaptive underwear. These underwear items have snaps on the side, making them easier for parents and children to pull on and off.

Cultural and Parental Differences in Timing

As a side note, parents also need to consider their culture and personal preferences when deciding at what age a child should start wearing underwear. It does make a difference.

Global Perspectives on Potty Training

Certain cultures believe that a child as young as two should know to wear underwear. On the other hand, other cultures believe a child should be over five before being introduced to underwear. There are many reasons for both these types of cultures and their beliefs. Parents should take them into consideration because for them, there might be societal implications for themselves or their children.

Parental Pressure vs. Child’s Pace

Every parent should carefully consider the pace their child might be comfortable with when trying something like underwear. Regardless of what parents believe, they shouldn’t pressure their children. Doing so will only harm the child mentally and delay their development.

Frequently Asked Questions (FAQs)

1. What is the earliest age a child can start wearing underwear?

While some toddlers show readiness as early as 18-24 months, most children begin transitioning between 2 and 3 years old. Early starters typically display strong bladder control and verbal cues about bathroom needs. However, forcing underwear before readiness can backfire—wait for clear signs of interest and physical capability.

2. Should I use training underwear or regular underwear first?

Training underwear (absorbent with thicker fabric) helps minimize messes during early potty training. However, regular underwear may accelerate learning since kids feel the wetness more distinctly. Many parents use training underwear at first, then switch to regular styles once their child has fewer accidents (usually within a few weeks).

3. What should I do when kids refuse underwear?

First, rule out discomfort (tags, tight elastic, or irritating fabrics). Let your child pick fun designs they love to boost interest. If resistance continues, try a gradual approach—start with underwear for short periods during playtime, then increase the duration as they grow more comfortable. Avoid power struggles, as stress can delay progress.

4. How long does it take for a child to fully adjust to underwear?

Most children adapt to daytime underwear within 4-8 weeks of consistent practice, though accidents remain common initially. Depending on hormonal development, nighttime dryness often takes longer (months to years). Patience is key—about 15% of kids occasionally wet the bed at age 5.

Conclusion

The age at which a child starts wearing underwear is between three and five, but that number isn’t set in stone. Instead of relying on age alone, parents should look for signs such as physical and mental maturity to better understand. When parents transition from diapers to underwear, they must find the right fit. The best bet is made from a 100% cotton blend that is breathable and moisture-wicking, if possible, to ensure comfort and movement for the child.

The transition will come with challenges that any parent can overcome calmly. When accidents happen, parents need to understand and support their children to help them learn. With consistency and encouragement, your child will soon confidently embrace their “big kid” underwear!