The front soft spot usually closes between 7 and 19 months, with many babies reaching closure around 13 to 14 months.
The anterior fontanelle is the larger soft spot near the top front of a baby’s head. It can feel strange the first time you notice it, yet it’s a normal part of early skull growth. Parents often spot it in the newborn weeks, then start wondering when it will stop feeling soft and open.
For most babies, that happens during late infancy. There is a wide normal range. Many close during the first year and a half, while some healthy babies stay open longer. One month by itself does not tell the whole story. Pediatricians pair the timing with head growth, skull shape, development, and how the soft spot feels during the exam.
Anterior Fontanelle Closure Age And The Normal Range
The skull does not seal shut in one sudden step. The bones slowly grow toward each other while the brain keeps expanding during infancy. So the anterior fontanelle usually gets smaller bit by bit, not all at once.
A soft spot that is still open at 9 months can be normal. One that is closing around a first birthday can be normal too. Many babies are closed by 18 months. A small number still have a tiny opening closer to age 2 and still turn out fine, especially when growth and the rest of the exam stay on track.
Why The Range Feels So Broad
Babies do not follow one tidy calendar. The size of the soft spot at birth varies. Skull shape shifts after delivery. Brain growth moves fast in the first year, and the tissue between skull bones changes over time. That is why one baby may have a barely noticeable opening by 10 months while another still has a clear gap at 15 months.
Timing is just one clue. Doctors pair it with head circumference, overall growth, muscle tone, feeding, sleep, and age-based skills. A slightly late closure with normal growth may be far less worrisome than a fontanelle that looks tense, sunken, or paired with a sharp change in head size.
What “Closed” Usually Feels Like
Closure is not an on-off switch. In many babies, parents first notice that the opening feels smaller and less easy to find. Then the edges seem closer together. After that, the gap becomes hard to feel at all.
When your baby is calm and upright, the area should usually feel soft and flat, or just a touch curved inward. A light pulse can be felt at times. That can be normal.
When Timing Needs A Closer Check
A late-closing anterior fontanelle does not automatically point to illness. Still, timing can matter when it comes with other findings. The range listed by MedlinePlus on cranial sutures places usual closure sometime within 7 to 19 months, while the AAFP review on abnormal fontanel findings reports a median closure age of 13.8 months and lists several conditions linked with delayed closure.
Those conditions can include congenital hypothyroidism, rickets, achondroplasia, Down syndrome, and raised pressure inside the skull. That list can sound heavy on paper, but the full picture matters more than one age marker. A baby with steady head growth, a normal exam, and no warning signs may simply be on the later side of normal.
| Age | What Often Happens | What Usually Fits The Normal Range |
|---|---|---|
| Newborn | The front soft spot is easy to find and may look larger than expected. | Wide variation in size is normal right after birth. |
| 1 to 2 months | The area may seem about the same size, even while head shape rounds out. | There is no need for it to shrink fast. |
| 3 to 5 months | Some babies start to show a smaller opening. | An open fontanelle is still routine at this stage. |
| 6 to 8 months | The gap may feel smaller, though it can still be easy to feel. | Plenty of healthy babies still have a clear soft spot. |
| 9 to 12 months | Closure often becomes more noticeable. | Open or partly open can still fit the usual range. |
| 13 to 14 months | Many babies are near closure around this point. | This sits close to the median age reported in the medical literature. |
| 15 to 18 months | A lot of babies finish closing during this window. | This is still a standard time for closure. |
| 19 to 24 months | A small number still have a tiny opening. | It may still be fine, though doctors often check the rest of the growth pattern more closely. |
Signs That Merit A Pediatric Visit Soon
Make a sooner appointment if the soft spot is open and you notice one or more changes that feel off. Timing alone is one thing. Timing plus symptoms is another.
- It looks full or bulging while your baby is calm and upright.
- It looks clearly sunken and your baby is feeding poorly or making fewer wet diapers.
- The head size starts rising faster than expected.
- The skull shape changes quickly or feels ridged along the sutures.
- Your baby has fever, unusual sleepiness, repeated vomiting, or new irritability.
- The soft spot seems closed early and head growth slows.
Routine well-child visits matter here. The AAP schedule of well-child care visits gives doctors repeated chances to measure head growth and feel the fontanelle across infancy, not just at one snapshot in time.
| Finding | What It Can Point To | Usual Next Step |
|---|---|---|
| Soft spot still open at 12 months | Often normal variation | Track head growth and recheck at the next visit. |
| Still wide open past 18 months | Normal late closure or an underlying growth issue | The doctor may pair the exam with growth history and, at times, lab work or imaging. |
| Bulging while calm | Raised pressure inside the skull or illness | Same-day medical advice is wise. |
| Sunken appearance | Fluid loss or dehydration | Check feeding, wet diapers, and get medical advice. |
| Closed early with poor head growth | Early suture fusion can be one concern | Prompt pediatric assessment is needed. |
| Open fontanelle plus delayed growth or low tone | May fit a broader medical pattern | The doctor may order targeted tests based on the full exam. |
How Doctors Judge Whether The Soft Spot Is On Track
The fontanelle is never checked by itself. Doctors measure head circumference again and again, then plot it over time. They assess skull shape, feel along the sutures, and compare the head growth pattern with weight, length, and development.
They ask practical questions too. Is feeding going well? Has the baby met expected skills for age? Is there vomiting, poor growth, floppy tone, or a head size that is racing upward? A normal answer pattern often lowers concern even when the fontanelle is still open a little longer than average.
If a closer workup is needed, the next step depends on what the doctor finds. A baby with an open fontanelle may have an ultrasound through that opening. In other cases, blood tests or other imaging may be used. The plan changes with the child in front of the doctor, not with one age number alone.
What Parents Can Watch At Home
You can lightly touch the soft spot during normal care. Gentle handling, shampooing, and brushing do not hurt it. What helps most is noticing patterns rather than checking it over and over through the day.
- Notice whether the spot is flat, gently curved inward, or suddenly looks full.
- Watch your baby’s feeding, wet diapers, and energy.
- Bring up any fast change in head shape or head size.
- Keep regular checkups even when your baby seems well.
At What Age Does The Anterior Fontanelle Close? Plain Answer
If you want the clearest age answer, use this: the anterior fontanelle usually closes between 7 and 19 months, and many babies close around 13 to 14 months. Closure by 18 months is routine. A tiny opening near age 2 can still fall within normal variation, though that is a good time for the doctor to double-check growth and the rest of the exam.
So the honest reply is not one single month. It is a range. That range is broad, and the child’s full growth pattern says far more than the calendar by itself.
References & Sources
- MedlinePlus.“Cranial sutures.”Lists the usual closure window for the anterior fontanelle and gives medical context for infant skull growth.
- American Academy of Family Physicians.“The Abnormal Fontanel.”Reports the median closure age and outlines conditions linked with delayed or abnormal fontanel findings.
- HealthyChildren.org / American Academy of Pediatrics.“AAP Schedule of Well-Child Care Visits.”Shows the infant well-visit schedule where head growth and fontanelle checks are tracked over time.
Mo Maruf
I created WellFizz to bridge the gap between vague wellness advice and actionable solutions. My mission is simple: to decode the research and give you practical tools you can actually use.
Beyond the data, I am a passionate traveler. I believe that stepping away from the screen to explore new environments is essential for mental clarity and physical vitality.