Short answer: about four minutes for most children between three and eight.
Longer answer: the length matters far less than the shape. A ten-minute story that winds down properly will settle a child better than a two-minute one that ends on a bang.
Why four minutes
Four minutes is long enough to feel like a proper story — a beginning, something happening, an ending — and short enough that a tired child can hold attention to the end without a second wind.
It also matters for the adult. Bedtime works best when it is repeatable on a bad night. A four-minute story is one you can still do at half nine after a long day. A twenty-minute chapter is one you start skipping, and a routine you skip stops being a routine.
The shape matters more
Most children's stories are built to entertain — they get faster, louder and funnier towards the end, because that is what makes a child laugh. At three in the afternoon that is exactly right. At bedtime it is working directly against you.
A bedtime story wants the opposite arc. Whatever happens should happen early. The last third should be quieter, slower, and lower stakes than the first. Nothing should be resolved in the final line, because a resolution is exciting.
The test is simple: read the last paragraph on its own. If it would make a child sit up, it is the wrong ending for bedtime.
Reading it so it works
- Start at normal volume and drop. Not a whisper — children strain to hear a whisper, and straining is alert. Just a little quieter with each page.
- Slow down rather than softening. Longer gaps between sentences do more than a gentler voice.
- Do fewer voices as you go. A big character voice on page one is fine. On the last page it wakes them up.
- Do not ask questions at the end. "What do you think happened next?" is a lovely thing to ask at any other time of day.
"One more story"
Almost always a bid for more time with you rather than more plot. Which means a second story does not really satisfy it, and a third will not either.
What tends to work better is naming it and giving a smaller version: two minutes of quiet company, lights already off, no new story. Most children take that deal, because the thing they wanted was the company.
It also helps to say the number at the start. "One story tonight" said before you begin lands very differently from "no" said afterwards.
Re-reading is not a problem
Children ask for the same story night after night because knowing what happens is the point. There is no suspense to keep them awake, and the familiarity itself is settling. A child who wants the same story for three weeks is not stuck — they have found the one that works.
The ten stories in our Bedtime Stories & Colouring Book are each written to about four minutes aloud, with the last few paragraphs deliberately quieter and shorter than the first.