A toddler is a child aged about 1 to 3 years (roughly 12 to 36 months): the CDC splits its parenting tips for this stage into “Toddlers (1–2 years old)” and “Toddlers (2–3 years old)”, and its next page covers “Preschoolers (3–5 years old)” (Source: CDC). The name comes from “toddling,” the unsteady early walk.
Key takeaways
- Toddler = roughly 1 to 3 years old (about 12–36 months): the ages of the CDC's two toddler pages, 1–2 and 2–3 years.
- The stages parents hear most: baby/infant (birth–12 months), toddler (1–3 years), and preschooler (3–5 years).
- In US clothing, “toddler” sizes are labeled 2T–4T — but a child in the first year of toddlerhood is often still in 12M–24M.
- 24M and 2T are the same age yet cut differently; that overlap trips up a lot of parents.
- European sizes are simply the child’s height in centimeters (80, 86, 92, 98, 104…), which is easier to shop than a guessed age.
- The number on the tag is a label, not a promise: our baby and toddler Size Index found the same label can fit very different bodies. Buy by measurement.
What age is a toddler?
A toddler is a child roughly 1 to 3 years old — about 12 to 36 months. The U.S. Centers for Disease Control and Prevention (CDC) splits its toddler parenting tips into Toddlers (1–2 years old) and Toddlers (2–3 years old), and starts its next page at Preschoolers (3–5 years old) (Source: CDC). The word itself comes from “toddle” — the short, unsteady steps of a new walker. The CDC's toddler pages run up to age 3.
These age ranges are general labels for shopping and everyday conversation — not a developmental assessment of any individual child. Children reach milestones at their own pace. If you have any question about your child’s growth, walking, speech, or development, please talk to your pediatrician. This article is general information, not medical advice — see our medical disclaimer.
About the sources: the CDC material on this page (its age-group page titles, quoted unchanged) was developed by the CDC and is otherwise available on the CDC website for no charge. Use of CDC material on this page, including links to CDC web pages, does not imply endorsement by CDC, ATSDR, HHS or the United States Government of Babbez or its products or services.
What are the baby, toddler, and preschooler age bands?
The three stages parents hear most run in a simple sequence: baby/infant to about the first birthday, toddler from 1 to 3, and preschooler from 3 to 5. Here is how the common age bands line up with the US clothing sizes you will see on the label.
| Stage | Typical age | Common US clothing sizes |
|---|---|---|
| Baby / infant | Birth–12 months | Newborn, 0–3M, 3–6M, 6–9M, 12M |
| Toddler | 1–3 years (12–36 months) | 12M–24M early on, then 2T–4T |
| Preschooler | 3–5 years | 4T–5T, then kids’ 5–6 |
Note the overlap: a 1-year-old has just entered toddlerhood but usually still wears baby-labeled 12M or 18M. The dedicated “toddler” cut (the 2T–4T labels) is built for a child who is walking, running, and often potty-training — roomier through the seat and a little longer in the leg than the same-age baby size.
When does a baby become a toddler, and what comes after?
In the CDC's age groups, a baby becomes a toddler at 1 year of age: its infant tips cover “Infants (0–1 years)” and its toddler tips start at “Toddlers (1–2 years old)”. The next stage starts at 3, with “Preschoolers (3–5 years old)” (Source: CDC). These are age labels, not an assessment of any child. For clothes at each stage, see our toddler clothes guide (1–3 years) and our preschool clothes guide (3–5 years).
What clothing size does a toddler wear?
Most toddlers wear 2T, 3T, or 4T, with the first stretch of toddlerhood (roughly 12–24 months) still in 12M, 18M, and 24M. In the UK, toddler clothes are usually labeled by age range (12–18 months, 18–24 months, 2–3 years) rather than 2T–4T. As a rough guide, 2T suits many 2-year-olds, 3T many 3-year-olds, and 4T many young 4-year-olds — but this tracks a child’s size, not the candles on the cake. For a size-by-age deep dive on the most-asked toddler year, see our guide to what size a 2-year-old wears. Because the same label behaves differently from brand to brand, the safest move is to shop by your child’s height and weight rather than the age printed on the tag — more on that below.
What is the difference between 24M and 2T?
They target the same age — a roughly 2-year-old child — but they are cut for different bodies. 24M (24 months) is the top of the baby range: it is shaped for a rounder tummy and the extra room a diaper (nappy) needs, and it snaps or has wide necklines for easy changes. 2T (2 toddler) is the bottom of the toddler range: slimmer through the middle, a touch longer in the arm and leg, and designed for a mover who is often potty-training. If your child is out of diapers and on the go, 2T usually fits better; if they are still in diapers and on the shorter side, 24M often wins.
How do European toddler sizes (height in cm) convert to US sizes?
European brands skip age labels and print the child’s height in centimeters instead — so a size 92 is built to fit a child up to about 92 cm tall. The sizes step up roughly every 6 cm (80, 86, 92, 98, 104…), and the number is the tallest height the garment is meant to fit. That is actually easier than guessing an age: measure your child’s standing height and read the label directly. The table below maps the published European height sizes to an approximate age and the closest US label. Treat these as approximate — they vary by brand, and the US kids’ labels above 4T diverge the most.
| EU size (height) | Fits height | Approx. age | Closest US label |
|---|---|---|---|
| 80 | 75–80 cm | 12–18 months | 12–18M — what size is 80? |
| 86 | 81–86 cm | 18–24 months | 18–24M |
| 92 | 87–92 cm | — | 24M / 2T |
| 98 | 93–98 cm | — | 2T–3T |
| 104 | 99–104 cm | — | 4T |
A dash (—) means we have no verified age for that size: go by height. That covers the toddler range; for the full chart from newborn (50) to age 10 (140), see our European and international size conversion chart (50 to 140).
For the number 80 specifically, we keep a dedicated breakdown — see what size 80 is in baby clothes. And if you would rather not do the math, our free Size Finder turns a weight into the size whose typical range (the median across the 27 brand charts in our Size Index) covers it.
Why does the same size label fit differently across brands?
Because the label is a marketing convention, not a standardized measurement — and the gap is bigger than most parents expect. When we built the Babbez Size Index (30 brands sold in the US, September 2026), we found the same printed label spans a wide range of real bodies. The “3–6M” label alone topped out anywhere from 14.5 lb to 20 lb depending on the brand (28 brands print a 3–6M weight), and “18–24M” ranged from about 26 lb to 32 lb (26 brands). That is why a toddler can be a comfortable 2T in one label and swimming in another. The fix is simple: shop by your child’s current height and weight, not the age on the tag. Our Size Finder and the full Size Index do that comparison for you, and for feet, our baby and toddler shoe size chart works the same way.
Questions parents ask
What age is considered a toddler?
About 1 to 3 years old, or roughly 12 to 36 months. The CDC splits its toddler parenting tips into two pages, Toddlers (1–2 years old) and Toddlers (2–3 years old).
Is a 1 year old a toddler or a baby?
In the CDC's age groups, a 1-year-old is a toddler: its toddler tips start at Toddlers (1–2 years old). A new 1-year-old often still wears baby-labeled 12M or 18M clothing rather than 2T.
What size clothes does a 2 year old wear?
Many 2-year-olds wear 2T, but size tracks a child's height and weight, not their age. Because the same label varies by brand, measure your child and shop by size. Our Size Finder and 2-year-old size guide walk through it in detail.
What does the number mean on European baby clothes?
European brands print the child's height in centimeters instead of an age. A size 92 is built to fit a child up to about 92 cm tall, and sizes step up roughly every 6 cm. Measure your child's standing height and read the label directly.
Is 24 months the same as 2T?
They target the same age but are cut differently. 24M is the top of the baby range, shaped for a rounder tummy and diaper room. 2T is the start of the toddler range, slimmer and a little longer for a walking, potty-training child.
What comes after the toddler stage?
Preschool age. In the CDC's age groups, the stage after its two toddler pages is Preschoolers (3–5 years old).
Is a 5-year-old a toddler?
No, not in the CDC's age groups: its Preschoolers (3–5 years old) page covers children from 3 to 5 years old.
Sources: U.S. Centers for Disease Control and Prevention (CDC), Positive Parenting Tips: Infants (0–1 years), Toddlers (1–2 years old), Toddlers (2–3 years old) and Preschoolers (3–5 years old) (last reviewed Feb. 20, 2026, Feb. 20, 2026, Jan. 29, 2026 and Feb. 20, 2026), page titles and last-reviewed dates read October 22, 2026; European (EN 13402) height-based garment sizing convention. Babbez Size Index (30 brands sold in the US, September 2026). For any question about your child’s growth or development, consult your pediatrician; see our medical disclaimer.