15-Month-Old: Milestones and Development

May 3, 2023
 minutes read
Written by
Mandy Treeby
Chief Baby Sleep Consultant
Medically reviewed by
Elissa Gross, DO
Board Certified Pediatrician & Lactation Consultant

Introduction: As your child grows and reaches the 15-month mark, you'll witness an array of exciting developments in their growth, motor skills, language abilities, and behavior. In this article, we'll delve into the milestones to expect at this age, and also provide guidance on how you can support your little one through these transformative moments and milestones.


Sleep and Nap Transitions: Finding the Balance

At 15 months, toddlers are undergoing a significant sleep transition, moving from multiple daily naps to just one nap per day. This single daily nap typically lasts between 1.5 to 3 hours, depending on your child's individual needs. Despite this change in daytime sleep patterns, your toddler will still require a total of 12 to 14 hours of sleep per day, which includes nighttime sleep.

During this transition period, it's crucial to observe your child's sleep cues and adjust their sleep schedule accordingly. Toddlers may show signs of tiredness or crankiness when they're ready for a nap or bedtime. By closely monitoring their behavior, you can create a tailored sleep schedule that supports their overall growth and development.

How to support your 15-month-old with sleep:

  • Ensure a consistent bedtime routine. This helps your 15-month-old toddler establish healthy sleep habits. A predictable routine can include activities such as a warm bath, reading a book, or singing lullabies, allowing your child to associate these activities with bedtime. Consistency in both the activities and the timing will help signal to your child that it's time to wind down and prepare for sleep.
  • Create a calm sleep environment, essential for promoting restful sleep . Ensure that the room is dark, quiet, and at a comfortable temperature. Consider using blackout curtains or a white noise machine if necessary. Maintaining a clutter-free, cozy space can help your child feel safe and secure, making it easier for them to fall asleep and stay asleep.
  • Be patient and attentive to their individual sleep needs. Each child is unique and may require different amounts of sleep or a different sleep schedule. Observe your child's sleep patterns and adjust their routine as needed to ensure they get the rest they need.

Weight and Height

At 15 months, the average weight and height for boys and girls can vary slightly. Keep in mind that these values are just averages, and each child's growth is unique. However, based on World Health Organization (WHO) growth charts, the approximate average values for 15-month-olds are as follows:

Girls: average weight 21.9 pounds (9.9 kg) and average height: 30.5 inches (77.5 cm).

Boys: average weight: 23.2 pounds (10.5 kg) and average height: 31.1 inches (79 cm).

Remember that growth trajectories can differ significantly among children. Your pediatrician will monitor your child's growth and development at regular check-ups and can provide personalized guidance based on their unique growth patterns. Factors such as genetics, nutrition, and overall health can influence a child's growth rate. Some children may experience growth spurts, while others may grow more gradually over time. It's essential to focus on your child's individual progress and avoid comparing them to others.

Walking, Motor Skills, and Language Skills: A World of Discovery

Most toddlers walk confidently by this age, and some may even attempt to run. Their curiosity and desire to explore the world around them drive their physical development, making this an ideal time for parents to support their child's gross motor skills.

Fine motor skills also continue to develop during this period. Toddlers may start to stack blocks, use utensils, and engage in more intricate hand-eye coordination tasks. Providing age-appropriate toys and activities that promote fine motor skills can help support their development in this area.

Language skills are another significant milestone at 15 months. Toddlers' vocabulary typically grows, and they may begin to form simple sentences or follow simple instructions. They might start to understand and use a few words or phrases, which allows them to communicate their needs more effectively.

To support your child's motor and language skills at 15 months:

  • Celebrate milestones: Encourage their efforts and celebrate achievements to build self-confidence.
  • Engage in development-promoting activities: Provide opportunities for motor and language skill development through play and conversation.
  • Create a safe environment: Childproof your home and offer age-appropriate toys for exploration and learning.
  • Encourage imitation: Model proper speech and actions for your child to mimic.
  • Use everyday activities as learning opportunities: Describe actions and name objects during daily routines to expose your child to new vocabulary.
  • Play interactive games: Choose games that teach new words, directions, and social skills.
  • Encourage pretend play: Provide props and materials for imaginative play, which helps develop language and cognitive skills.
  • Introduce diverse books: Read regularly and choose books with engaging stories and illustrations.
  • Limit screen time: Prioritize face-to-face interactions and active play over passive screen time.
  • Connect with other children: Arrange playdates or attend group activities for social interaction and language skill development.

By supporting your child's motor and language development at 15 months, you can help them build a strong foundation for future learning and growth.

Your 15-month-old teething development

As your child reaches the 15-month mark, they may experience the eruption of their first molars, which can cause varying levels of discomfort or irritability. It is essential to remember that each child's teething experience is unique, and the symptoms and duration of teething may differ significantly. By understanding the unique nature of each child's teething experience and offering support and comfort during this time, you can help your child navigate this challenging phase with greater ease.

To support your child during the teething phase, consider strategies such as observing for teething signs like drooling, fussiness, disrupted sleep, or decreased appetite, and providing comfort when needed. Offer healthy teething snacks, maintain good oral hygiene, and provide a soothing gum massage to help alleviate discomfort. Be mindful of irritants, encourage self-soothing techniques, and monitor for complications.

To support your child during the teething phase, consider the following strategies:

  • Observe for teething signs like drooling, fussiness, disrupted sleep, or decreased appetite, and provide comfort when needed.
  • Offer healthy teething snacks: such as chilled/frozen fruits and vegetables to help soothe sore gums. Ensure the pieces are age-appropriate and not a choking hazard.
  • Maintain good oral hygiene: use a soft cloth or baby toothbrush to keep their mouth clean and reduce infection risk.
  • Avoid potential irritants like acidic foods or beverages that can aggravate sensitive gums during teething.
  • Teach your child techniques like sucking on their fingers or a pacifier to cope with discomfort independently.

If you notice any concerning symptoms, consult your pediatrician for guidance.

Feeding: Nurturing Their Individual Tastes

At 15 months, toddlers are typically eating a variety of solid foods, including fruits, vegetables, proteins, and grains. They are encouraged to practice self-feeding with child-safe utensils, developing independence and fine motor skills. It is important to remember that food preferences and eating habits vary among children, so each toddler's experience will be different.

To support your child's feeding and nutritional development, offer a balanced diet that meets their nutritional needs. Encourage them to use child-safe utensils for self-feeding, fostering their autonomy and dexterity. Lastly, be patient and flexible with their individual food preferences, adapting to their tastes while promoting healthy eating habits.

Play: Unique Paths to Learning and Exploration

Play at 15 months serves as a unique path for learning and exploration, promoting cognitive, motor, and social development in toddlers. Providing age-appropriate toys, puzzles, and creative activities tailored to your child's interests will help stimulate their curiosity and growth. Encouraging outdoor play is essential for physical development and offers opportunities for new experiences.

To support your child's play and learning, engage in activities that align with their individual interests and developmental needs. Encourage social interactions and playdates with other children to foster communication and social skills. Offer a variety of learning opportunities through play and exploration, allowing your child to discover and learn at their own pace.

Behavioral development at 15 months old

As your toddler reaches 15 months, behavioral development will become an important aspect of their growth. Your child is asserting their independence and it can happen more often that they throw a tantrum when things don’t go their way. It's important to understand that each child's temperament and emotional responses will vary.

To get through this over time, make sure to set clear boundaries, offer choices when possible, and remain patient and calm during these emotional outbursts. By understanding and addressing the root causes of tantrums, you can help your child develop healthy emotional regulation.

At this age your toddler may also be at the height of separation anxiety . This can manifest in different ways, and each child experiences separation anxiety differently. To ease the transition and support your child through this period, gradually increase the time spent apart, maintain a consistent goodbye routine, and reassure your child of your return. Being sensitive to their unique needs and emotions will help foster a secure attachment and build trust in your relationship.


American Academy of Pediatrics. Caring for Your Baby and Young Child: Birth to Age 5, 7th ed. (New York: Bantam Books, 2019).

American Academy of Pediatrics. The Wonder Years. (New York: Bantam Dell, 2006).

KidsHealth. “Your Child’s Checkup: 15 Months.”

healthychildren.org. “Good Oral Health Starts Early.”

healthychildren.org. “How to Share Books With Your 15- to 17-Month-Old.”

zerotothree.org. “12–15 Months: Your Child’s Development.”

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At 15 months, your toddler may be walking confidently, attempting to run, developing fine motor skills, using simple words, and understanding simple instructions. However, remember that each child develops at their own pace.

A 15-month-old might have a vocabulary of around 10 words, including names of familiar people, common objects, and simple requests. Keep in mind that language development varies among children.

The average 15-month-old may say around 10 words. However, this can vary widely among children, and some may have a larger vocabulary, while others may be slower to develop language skills.

If your 15-month-old isn't talking, it's essential to monitor their overall development and communication skills. While some children may be late talkers, it's always a good idea to consult your pediatrician to rule out any potential developmental concerns.

Red flags for 15-month-olds may include a lack of interest in social interactions, not responding to their name, not pointing at objects, or having difficulty with motor skills. If you notice any of these concerns, consult your pediatrician.

Some toddlers may experience sleep regression around 15 months. It's essential to maintain a consistent sleep routine and address any potential causes, such as teething or developmental milestones , that may be disrupting their sleep.

To help your 15-month-old sleep through the night, establish a consistent bedtime routine, create a calm sleep environment, and be patient and attentive to their individual sleep needs.

The ideal bedtime for a 15-month-old may vary, but many toddlers do well with a bedtime between 7 and 8 p.m. Consider your child's individual sleep needs and daily schedule when determining the best bedtime for them.

Teaching your 15-month-old to listen involves setting clear boundaries, offering choices when possible, using age-appropriate language, and being patient and consistent in your expectations.

Focus on teaching your child motor and language skills through play, exploration, and daily routines. Offer age-appropriate challenges and learning opportunities, and encourage social interactions with other children. Some games to play with your 15-month-old include "peek-a-boo," "pat-a-cake," "Simon says," and simple puzzles. Engage in activities that promote motor, cognitive, and language development.

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