To write a children's book, choose the category first, because the reader's age decides the length, the format, the vocabulary and who holds the book. The table below gives each category's readers and a suggested length. Then give a child a problem that matters to them, let the child solve it, and tell it in a voice that sounds like them, not like an adult explaining.
Children's book categories at a glance
| Category | Who it's for | Suggested length | What it looks like |
|---|---|---|---|
| CategoryBoard book | Who it's forBabies and toddlers, up to about 3 | Suggested lengthUp to 100 words | What it looks likeCard pages; mostly reissued picture books, concept books and spin-offs |
| CategoryPicture book | Who it's forChildren who are read to, about 3 to 7 | Suggested lengthUp to 600 words; nonfiction longer | What it looks likeUsually 32 pages, a picture on every spread |
| CategoryEarly reader | Who it's forChildren starting to read alone, about 5 to 7 | Suggested lengthUp to 1,500 words | What it looks likeOften 48 to 64 pages, short sentences, numbered levels |
| CategoryChapter book | Who it's forAbout 7 to 9 | Suggested lengthAbout 4,000 to 15,000 words | What it looks likeShort chapters, some pictures, often a series |
| CategoryMiddle grade | Who it's forAbout 9 to 12, with upper middle grade reaching 13 and 14 | Suggested length15,000 to 35,000 words for younger readers; 35,000 to about 65,000 for most; up to 80,000 for upper middle grade fantasy, science fiction and historical | What it looks likeFull novels, any genre |
| CategoryYoung adult | Who it's forTeenagers, from about 13 or 14 | Suggested lengthUp to 80,000 words; up to 100,000 for fantasy, science fiction and paranormal | What it looks likeTeenage heroes, any genre |
Category is not genre. A middle-grade mystery has both, and an agent who takes adult fantasy may not take young adult fantasy. The list of book genres covers the genres; this guide is about writing for an age.
What each category asks of you
Board books
Board books are for babies and toddlers, and few start as a writer's manuscript. An article on Harold Underdown's site The Purple Crayon finds that most are picture books reissued on card, simple concept books made by publishers or written to order, and spin-offs of TV shows and films. Its advice is not to submit a text as a board book at all. Write a very short picture book for the youngest listeners, under 300 words, and let the publisher choose the format.
Picture books
A picture book is read aloud by an adult while a child looks, usually across 32 pages and 12 to 15 spreads. The text leaves what things look like to an illustrator the publisher chooses, and ends spreads where a page turn adds a surprise. The American Library Association's Caldecott Medal, given since 1938, goes to the illustrator. The full method, with a sample manuscript, is in how to write a picture book.
Early readers
Early readers, or easy readers, are the first books children read alone, so the words carry more weight than the pictures. Underdown's guide asks for short, simple sentences and stories that aren't too long or complicated, often in 48 to 64 pages. Publishers sell them as leveled series, such as HarperCollins's I Can Read! (My Very First to Level 4) and Random House's Step into Reading (Steps 1 to 5). The vocabulary is limited on purpose: Dr. Seuss wrote The Cat in the Hat (1957) for beginning readers, and the finished book uses 236 different words. A readability score can flag long sentences, but a child reading aloud is the real test of which words they can sound out.
Chapter books
Chapter books sit between early readers and novels. Mary Kole puts their readers at roughly seven to nine and their length at about 4,000 to 15,000 words, in short chapters that end with a reason to keep reading. Pictures still appear, but fewer. Series are common on this shelf, from Judy Moody to Ivy + Bean, so a hero and a situation that could carry more than one book are worth having.
Middle grade
Middle grade is the novel for readers of about 9 to 12, and its heroes are usually children too, often at the older end of that range. Where middle grade ends is a market question as much as an age. In the US, where 14-year-olds usually start high school, a 14-year-old hero tends to signal young adult. But age is one signal among several: the voice, the hero's concerns and the reader you have in mind count as much, and Kole describes the edge as a gray area, with upper middle grade on one side and lower YA on the other.
The books can take on hard subjects but keep a light touch on romance, profanity and violence, without talking down to the reader. Lengths vary widely; see the table, and for other agents' ranges, how many words is a novel. The Newbery Medal, awarded by the American Library Association since 1922, defines children as readers up to and including fourteen, which takes in all of middle grade.
Young adult
Young adult (YA) is written for teenagers and about them, and is usually told close to the teenager's point of view, often in first person (see point of view). Underdown dates the category to the late 1960s, when writers began publishing more challenging novels for teens, and warns adults not to underestimate teen readers. Coming of age is its natural shape (see bildungsroman), and most genres have a YA shelf.
One premise, two shelves
The same premise changes shape with the reader's age. Here is one idea written as a picture book and as a middle-grade novel.
The premise. A family is moving out of the apartment above the grandfather's shoe-repair shop, and the shop is closing.
Picture book, about 500 words. On moving day, five-year-old Theo wants to take the shop's brass doorbell with him. Grandpa says the bell belongs to the door. Theo hides it in his sock drawer, then in a shoebox, and both times it jingles and gives him away. On the last spread he hangs it back on the door himself, for the next family, and takes one red shoelace instead.
Middle grade, about 40,000 words. Theo, twelve, learns in June that the building has been sold and the shop will close at the end of August. He starts a petition, runs a sidewalk sale with his best friend, Ines, and feuds with the new owner's daughter, who turns out to hate the move as much as he does. He doesn't save the shop. He does find out why his grandfather agreed to sell, and on the last day Theo is the one who locks the door.
The five-year-old's story fits one day and one building, and his choice is small and immediate, while the pictures carry the shop, the boxes and the bell. The twelve-year-old can make a plan, fail and make another, and the book has room for a friend, a rival and a secret. In both versions the decision that ends the story belongs to the child, and no adult solves it for him. The spread-by-spread work on the first version belongs to the picture book guide.
Eight steps for any age
- Choose one reader
Pick the category, then picture an actual child: a six-year-old who knows her letters but not chapter books, an eleven-year-old just allowed to walk to school alone. Write it down as a short reader card: the category, the reader's age, the length range and what the hero can and can't do alone.
- Read the shelf as it is now
Start with several books in the category from the last five years, and keep adding to the list as the project develops. Type out a short opening passage from one you admire, for your eyes only, to feel its rhythm. Classics are worth reading, but they won't show you what editors buy now.
- Give the child a child-sized problem
A lost library book, a best friend moving away, a secret that can't be kept. It must matter enormously to the character, whatever an adult would think of it.
- Let the child solve it
Adults can advise, block or watch. The decision that changes things belongs to the young hero.
- Find the voice
Tell it at the child's eye level: what they notice, what they find funny, what they can't say out loud. Plain words, never baby talk.
- Shape it to the category
Spreads for a picture book, levels for an early reader, short chapters with hooks for a chapter book, a full novel structure for middle grade and YA. Check the length against the table.
- Read it aloud and find readers
Find critique partners who write for the same age, for instance through an SCBWI regional chapter. If you test it on children, watch where they fidget rather than asking whether they liked it.
- Revise, then submit
Revise for clarity, length and the child's agency, then query agents who represent the category.
If you draft in Strokes, attach the reader card and a chapter to the Strokes Assistant and ask it to review the chapter against the card: words your reader may not know yet, sentences too long to read alone, places where an adult solves the problem. Then check its list with a child reading aloud.
What children's classics still teach
Four openings from public-domain children's books, each still a lesson.
Alice was beginning to get very tired of sitting by her sister on the bank, and of having nothing to do: once or twice she had peeped into the book her sister was reading, but it had no pictures or conversations in it, “and what is the use of a book,” thought Alice “without pictures or conversations?”
Carroll opens on the young reader's own complaint, and two paragraphs later a White Rabbit takes a watch out of its waistcoat-pocket. A children's book can be quiet, but Carroll doesn't make his reader wait long for something strange.
When Mary Lennox was sent to Misselthwaite Manor to live with her uncle everybody said she was the most disagreeable-looking child ever seen. It was true, too.
The narrator agrees with everybody, and the honesty is the hook. Mary is sour, spoiled and alone, and the book is the story of how she changes. A hero doesn't have to be likable on page one, only worth watching.
“Christmas won't be Christmas without any presents,” grumbled Jo, lying on the rug.
“It's so dreadful to be poor!” sighed Meg, looking down at her old dress.
“I don't think it's fair for some girls to have plenty of pretty things, and other girls nothing at all,” added little Amy, with an injured sniff.
“We've got Father and Mother, and each other,” said Beth contentedly from her corner.
Four sisters, four lines, four characters: Jo's bluntness, Meg's longing, Amy's grievance and, after three complaints, Beth's contentment. Here dialogue introduces a cast faster than description could, and a young reader can choose a sister in four lines.
Here is Edward Bear, coming downstairs now, bump, bump, bump, on the back of his head, behind Christopher Robin.
Read it aloud and the bumps fall where the stairs do, so the sentence comes down the staircase with the bear. A line written for the ear gives the adult reading it something to perform and the child listening something to wait for.
Common children's book mistakes
- The lesson first. A story built to teach sharing or kindness turns into a lecture with characters. Let the hero's choices carry the values.
- An adult in charge. The parent, teacher or wise grandparent who fixes it takes the story from the child.
- Writing down. Baby talk, every feeling explained, jokes aimed over the child's head at the parents.
- The wrong length. A 3,000-word picture book or a 120,000-word middle-grade novel is far outside any suggested range, and an agent may read it as a sign you haven't read the shelf.
- Slang and trends. They date fast. Keep the language plain, or invent your own.
How children's books get published
Agents are now the usual way in. Harold Underdown, in an article last updated in 2025, writes that writers for children now generally need one, and that most houses say they consider manuscripts only from agents or published authors. Some smaller publishers read unagented work; check each one's current submissions page, because open windows close. What you send depends on the category:
- Picture books go out as complete texts, without art unless you are the illustrator. The publisher chooses the artist.
- Early readers and chapter books go out as a finished manuscript, with a line on where a series could go if it could be one.
- Middle grade and YA are queried like adult novels: a query letter, the opening pages and a finished, revised manuscript.
For the querying itself, see how to get a literary agent and how to write a query letter.
Frequently asked questions
Are children's book word counts strict?
No. They are suggested ranges, and they differ between sources: editor Mary Kole's own figures have shifted between her 2009 list and her current guide. A text far outside its category's range is a harder sell, but series publishers and individual agents set their own limits, so check their guidelines before you submit.
What age is middle grade?
Middle grade is written for readers of about 9 to 12, and upper middle grade reaches 13 and 14. In the US, where 14-year-olds usually start high school, a 14-year-old hero tends to signal young adult. But the hero's age is one signal among several: the voice, the hero's concerns and the reader you have in mind also decide the shelf.
Do I need an illustrator to write a children's book?
Not if you submit to agents or traditional publishers. Send the text alone: for a picture book the publisher chooses the illustrator after offering a contract, and illustrated chapter books are handled the same way. You arrange the art yourself only if you self-publish. If you are an illustrator, you submit a dummy with sample art.
Is young adult a children's book?
It depends who is counting. Guides to children's publishing, such as Harold Underdown's, cover YA alongside picture books and middle grade. But the Newbery Medal defines children as readers up to and including 14, which reaches only the youngest end of YA. When you query, treat YA as its own category with its own word counts.
