Tracking your baby’s growth is an important part of parenting, especially during the first year. One of the most common questions parents ask is: What is the average size of 4 month old babies? Understanding this can help you ensure your child is growing well and meeting developmental milestones.
In this blog, we’ll cover the average weight, height, and head circumference for 4-month-old boys and girls, growth chart references, and tips to support your baby’s healthy development.
Why Tracking Baby Size Matters?
Your baby’s size — including weight, height (length), and head circumference — gives important clues about their overall health and nutritional status. Pediatricians track this data during regular check-ups using standardized growth charts developed by the World Health Organization (WHO) or the Indian Academy of Pediatrics (IAP).
While every baby is unique, knowing the average size of a 4 month old helps identify if your child is growing within a healthy range.
Average Size of 4 Month Old Baby (Boys and Girls)
Below are average growth parameters for 4-month-old babies, based on WHO growth standards commonly used in India:
Average Weight of a 4 Month Old Baby
| Gender | Average Weight (kg) | Weight Range (kg) |
|---|---|---|
| Boys | 6.4 kg | 5.1 – 7.8 kg |
| Girls | 5.8 kg | 4.5 – 7.3 kg |
Average Height (Length) of a 4 Month Old Baby
| Gender | Average Height (cm) | Height Range (cm) |
|---|---|---|
| Boys | 62.1 cm | 58.0 – 66.0 cm |
| Girls | 60.0 cm | 56.0 – 64.0 cm |
Average Head Circumference of a 4 Month Old Baby
| Gender | Average (cm) | Range (cm) |
|---|---|---|
| Boys | 41.5 cm | 39.0 – 43.5 cm |
| Girls | 40.5 cm | 37.5 – 42.5 cm |
Note: These are general averages. Some healthy babies may fall slightly above or below these ranges.
Indian Perspective on Baby Growth
In India, pediatricians often refer to IAP growth charts, which are adjusted for Indian children’s nutritional and genetic patterns. It’s important to have your baby’s measurements taken at each well-baby visit and plotted on a chart to observe their growth trend over time, rather than comparing single numbers.
What Affects the Average Size of a 4 Month Old?
Several factors influence how much a 4-month-old weighs or how tall they are:
- Birth weight and length
- Gender (boys tend to be slightly bigger)
- Feeding method (breastfed vs formula-fed)
- Parental genetics
- Overall health and nutrition
- Prematurity or birth complications
Don’t worry if your baby’s size is slightly different from the average. What matters most is steady growth over time.
How to Support Healthy Growth at 4 Months?
At 4 months, babies are becoming more active and alert. Here’s how you can support their growth:
1. Continue Exclusive Breastfeeding
Breast milk provides complete nutrition for the first 6 months. Formula is a suitable alternative if breastfeeding isn’t possible.
2. Track Developmental Milestones
By now, your baby may smile, roll over, and hold their head up. These are signs of normal development.
3. Regular Doctor Checkups
Attend monthly or scheduled checkups to monitor growth, vaccinations, and milestones.
4. Tummy Time
Helps strengthen neck and shoulder muscles, supporting overall physical development.
5. Watch for Growth Spurts
Babies may gain weight rapidly during growth spurts, often around 4 months.
When to Consult a Pediatrician?
While slight variations are normal, talk to your doctor if:
- Your baby hasn’t gained weight in over 2 weeks
- They are far below the average size of 4-month-old babies
- They’re not meeting developmental milestones
- You notice feeding difficulties or excessive sleepiness
Early detection of growth issues can lead to timely intervention.
Growth vs. Development
It’s important to distinguish physical growth (size) from development (skills and behavior). A baby growing slowly may still meet all cognitive or motor milestones. Pediatricians evaluate both aspects during well-child visits.
Final Thoughts
Understanding the average size of 4 month old babies is helpful, but it’s only one part of your child’s overall health journey. Focus on steady growth, active engagement, and timely checkups to ensure your baby is thriving.
Every child grows at their own pace — what’s most important is consistent love, care, and a healthy environment to help them flourish.
For more information on parenting, explore articles on our KidsCur site!
FAQs
Q 1: What is the average size of a 4-month-old baby?
Answer:
The average size of a 4-month-old baby varies by gender. Typically, boys weigh around 6.4 kg and measure about 62.1 cm in height, while girls weigh around 5.8 kg and are about 60 cm tall. Head circumference averages around 41.5 cm for boys and 40.5 cm for girls.
Q 2: Should I worry if my baby is smaller than the average size of 4 month old?
Answer:
Not necessarily. Every baby grows at their own pace. It’s more important to monitor consistent growth over time rather than comparing to exact averages. If your baby is active, feeding well, and meeting developmental milestones, minor size differences are usually normal. Always consult a pediatrician for guidance.
Q 3: How can I help my baby reach the average size of a 4-month-old?
Answer:
Ensure your baby receives proper nutrition through exclusive breastfeeding or formula feeding, give them plenty of tummy time, keep up with vaccinations, and attend regular pediatric checkups. A loving, stress-free environment also supports healthy growth and development.
