A kitten’s teeth are one of the most reliable ways to estimate its age, especially during the first six months of life. Kittens are born toothless, get their first baby teeth around 3 weeks, and complete the switch to permanent adult teeth by about 7 months. By knowing what to look for at each stage, you can narrow a kitten’s age to within a week or two just by opening its mouth.
Birth to 2 Weeks: No Teeth at All
Newborn kittens have completely bare gums. If you gently open a kitten’s mouth and see nothing but smooth, pink gum tissue, the kitten is likely under 2 weeks old. At this stage, other clues line up with the toothless mouth: the eyes are still closed (they begin opening around 8 to 12 days), the ear canals are sealed, and you may still see the remains of the umbilical cord. By around two weeks, the ears start to open and look small and rounded, but the gums remain empty.
3 to 4 Weeks: First Baby Teeth Appear
The very first teeth to push through are the tiny front incisors and the pointed canines (the “fangs”), which emerge at roughly 3 to 4 weeks of age. When you look inside the mouth, you’ll see small, needle-sharp points breaking through the gumline at the front of the jaw. Baby teeth are noticeably translucent compared to adult teeth, almost see-through at the tips, and extremely thin. At this same age, the ears will be standing upright for the first time and the kitten will start attempting wobbly walks.
If you see just the incisors and canines with no teeth further back in the jaw, the kitten is most likely between 3 and 4 weeks old.
5 to 6 Weeks: Premolars Fill In
Between 5 and 6 weeks, the baby premolars begin erupting behind the canines. These are the smaller chewing teeth along the sides of the mouth. The upper jaw gets three premolars on each side, while the lower jaw gets two on each side. Once all the baby teeth are in, a kitten has 26 deciduous teeth total.
A kitten with a full set of tiny, sharp, translucent teeth and no gaps along the gumline is typically 6 to 8 weeks old. At this point the baby blue eye color that all kittens are born with begins shifting. Kittens whose eyes have turned grey, green, or yellow are generally 7 weeks or older, which helps confirm what the teeth are telling you.
How Baby Teeth Look Different From Adult Teeth
This distinction matters because you’ll need to recognize which type of tooth you’re seeing to estimate age accurately during the transition period. Baby teeth are smaller, thinner, and sharper than permanent teeth. They often look slightly translucent or glassy, especially the incisors. Adult teeth, by contrast, are larger, more opaque, and have a creamy white or ivory color. The adult canines are noticeably thicker at the base.
During the transition months, you may spot both types of teeth in the mouth at the same time. It’s common to see a permanent tooth pushing up right next to a baby tooth that hasn’t fallen out yet. This “double tooth” appearance is a strong visual signal that the kitten is somewhere between 4 and 6 months old.
4 to 7 Months: Permanent Teeth Replace Baby Teeth
Starting around 4 months, the baby teeth begin falling out and permanent teeth take their place. The process follows roughly the same order the baby teeth came in: incisors first, then canines, then premolars. Most kittens have all their permanent teeth by 6 to 7 months of age. The full adult set includes 30 teeth, four more than the baby set, because cats gain four molars at the very back of the mouth that have no baby tooth predecessors.
Here’s what to look for at each stage of the transition:
- 4 months: The baby incisors at the front start loosening or falling out. You may see gaps where an incisor used to be, or a slightly larger permanent incisor pushing through.
- 5 months: The permanent canines begin emerging. The baby canines may still be present alongside them, giving the kitten a temporary “double fang” look.
- 5 to 6 months: Premolars are being replaced. The new premolars are wider and less needle-like than the baby versions.
- 6 to 7 months: The molars appear at the very back of the jaw. These are the last teeth to arrive. Once you can count four molars (one on each side, top and bottom), the kitten has its complete adult dentition.
Teething Signs That Confirm the Timeline
Behavior can back up what you see in the mouth. Kittens going through the transition to adult teeth often drool more than usual, chew on objects aggressively, and may paw at their muzzle or shake their head. These signs are most common between 4 and 6 months and happen because loose baby teeth irritate the gums. If a kitten is drooling heavily and you can wiggle a tooth with gentle pressure, it’s right in the middle of the teething window. Some kittens also eat less enthusiastically for a few days when a tooth is particularly loose.
After 7 Months: Using Wear Patterns
Once all 30 permanent teeth are in place, dental aging becomes much less precise. A kitten with a full set of bright white, unworn adult teeth and healthy pink gums is likely between 7 months and about 1 year old. After the first year, teeth gradually accumulate wear and tartar. Slight yellowing at the gumline and minor dulling of the tooth tips suggest a cat older than 1 to 2 years, but at that point teeth alone can’t pinpoint age with the week-by-week accuracy you get during kittenhood.
Other Physical Clues to Cross-Check
Teeth give you the best single estimate, but combining dental stage with a few other markers makes your guess more reliable. Weight is a useful backup: healthy kittens gain roughly one pound per month for the first several months, so a 2-pound kitten with only baby incisors and canines is most likely around 4 weeks old. Eye color is another checkpoint. All kittens start with blue eyes, and the permanent color (green, gold, copper) typically settles in by 8 weeks. A kitten with baby blue eyes and emerging front teeth is almost certainly under 6 weeks.
Ear shape changes alongside teeth as well. At 2 weeks, ears are small and rounded. By 3 weeks, when the first teeth appear, the ears point upward. By the time all baby teeth are in around 6 weeks, the ears look proportional to the head and fully erect. Putting these markers together with what you see in the mouth gives you a confident age estimate, even without a birth date on record.