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Kitten Age Chart

You can estimate a kitten's age from weight, eyes, ears and teeth. A newborn weighs 3–4 oz, eyes open at 7–10 days, ears stand up by about 3 weeks, and a kitten reaches about 1 lb at 4 weeks. Tick what you can see for an age range in weeks.

By Sikander Malik · Updated October 10, 2026 · Sources

oz
What can you see?

Estimated age

5–6weeks

Based on: weight (24 oz), eyes open, ears up, incisors, canines.

Weight alone isn’t reliable before 2–3 weeks. All baby teeth are in by about 8 weeks.

Estimates only, not veterinary advice. Ask your vet about your pet’s health.

How to use it

  1. Weigh the kitten if you can (ounces or grams). It helps most after 4 weeks.
  2. Tick the signs you can see: eyes open, ears up, which teeth are through, and whether it walks steadily.
  3. Read the age range in weeks and which signs drove it.
Close-up of a young tabby kitten against a light backdrop

Photo: Artem Makarov / Pexels

The formula, with two examples

We combine Alley Cat Allies' milestones. Each sign has an age it first appears, and weight after 4 weeks follows about 4–6 oz gained per week from 1 lb: weeks ≈ 4 + (weight in oz − 16) ÷ 5, shown as a range using 4 and 6 oz/week. Signs set the lower bound; weight sets the estimate once a kitten passes 4 weeks.

Example 1. A 24 oz kitten with eyes open, ears up, and incisors and canines through: weight gives 4 + 8/6 to 4 + 8/4, about 5.3 to 6.0 weeks, and the teeth agree, so about 5 to 6 weeks.

Example 2. An 8 oz kitten with eyes just opening and no teeth is about 1 to 1½ weeks.

What this calculator doesn’t cover

  • Health checks; a kitten that seems sick needs a vet now.
  • Orphan kitten feeding amounts; follow a sourced bottle-feeding guide.
  • Kittens older than about 6 months, where adult teeth are all in.
Kitten age, week by week
AgeWeightWhat you see
Under 12 hours3–4 ozUmbilical cord still wet
1–5 days3–5 ozCord dried and dropping off
1 week≈8 ozEyes start to open (7–10 days)
2–3 weeks9–12 ozIncisors come in (2½–3½ weeks)
3 weeks12–14 ozEars upright; canines come in (3–4 weeks)
4 weeks≈1 lbWalking, tail up; starts to explore
5–8 weeks1–2 lbPremolars in; all baby teeth by 8 weeks
After 4 weeks, kittens gain about 4–6 oz per week. Weight alone isn’t accurate before 2–3 weeks.
Source: Alley Cat Allies, Determining a Kitten’s Age.
When adult teeth come in
TeethAge
Incisors3–3½ months
Canines3–4 months
Premolars4½–6 months
Molars5–6 months
All adult teeth inBy 6 months
Source: Alley Cat Allies, Determining a Kitten’s Age.

Tips

  • If weight and teeth disagree, trust the teeth. Growth varies with nutrition, especially in orphans.
  • Weigh daily for orphan kittens; steady gain (about ½ oz a day early on) is a good sign.
  • Eyes are blue and ears are folded in the first couple of weeks, then both change around 3 weeks.

Questions owners ask

How can you tell how old a kitten is?
Use weight, eyes, ears and teeth together. Newborns weigh 3–4 oz with closed eyes; eyes open at 7–10 days; ears stand up by about 3 weeks; a kitten hits about 1 lb at 4 weeks. Teeth are the most reliable clue once they start coming in around 2½ weeks.
How much should a 4-week-old kitten weigh?
About 1 pound (around 14 to 16 oz). From there, kittens gain roughly 4 to 6 oz a week, so a 5-week-old is often 18 to 22 oz. Use weight alongside teeth and behavior, since individual kittens vary.
When do kittens open their eyes?
Between 7 and 10 days old. The eyes are blue at first and change to their adult color over the following weeks. If a kitten’s eyes are open, it is at least a week old, which helps narrow down a young kitten’s age.
When do kittens get their teeth?
Baby incisors come in around 2½ to 3½ weeks, canines (fangs) at 3 to 4 weeks, and premolars from about 5 weeks. All baby teeth are usually in by 8 weeks. Adult teeth then replace them between about 3 and 6 months.
When can kittens leave their mother?
Not before 8 weeks, and many shelters wait until 10 to 12 weeks. Kittens need this time to wean, learn from their mother and littermates, and build social skills. Early separation is linked to behavior problems later.
When do kittens lose baby teeth?
Baby teeth start falling out around 3 to 4 months as the adult set pushes through. Incisors go first, then canines and premolars, with all 30 adult teeth usually in by about 6 months. You may find tiny teeth or none at all, as many are swallowed.

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Sources

Estimates only, not veterinary advice. Ask your vet about your pet’s health.