Bedtime by Age: Work Backwards From Wake-Up Time

Bedtime charts circulate every autumn promising that a six-year-old waking at 7am must be asleep by 7.45pm. They're shared widely, they make a lot of parents feel like they're doing it wrong, and they're built on arithmetic you can do yourself in about ten seconds.

There is no universally correct bedtime. There's a range of sleep your child's age needs, a fixed time they have to be up, and a subtraction between the two. Here's how to do it properly — and why the answer matters less than what happens in the 45 minutes before it.

Sleep Needs by Age

These are the consensus ranges used by paediatric sleep bodies, covering total sleep in 24 hours including naps where relevant:

• 4–12 months: 12–16 hours (including naps)
• 1–2 years: 11–14 hours (including naps)
• 3–5 years: 10–13 hours (including naps)
• 6–12 years: 9–12 hours
• 13–18 years: 8–10 hours

Two things to hold onto. These are ranges, not targets — a child at the bottom of their band who wakes cheerful and gets through the day well is getting enough. And they're broad on purpose, because genuine variation between children is large. The ranges are guidance, not a diagnostic threshold; persistent sleep problems are worth raising with your GP rather than solving with a chart.

The Calculation

Three steps:

1. Start with the fixed point: the time your child must be awake on a school day. This is the one thing you can't move.
2. Subtract the sleep their age needs. Take the middle of the range to begin with and adjust later.
3. Subtract about 20 minutes for the time it actually takes to fall asleep.

Worked example: a seven-year-old who must be up at 7am and needs around 10 hours. Ten hours back from 7am is 9pm asleep. Twenty minutes earlier for falling asleep gives lights out at 8.40pm. And the wind-down needs to start around 8pm.

That last number is the one worth writing down, because it's the only one you actually control. You cannot make a child fall asleep at 9pm. You can start the wind-down at 8pm.

Why the Wind-Down Decides Everything

A child who goes from a tablet or a game of chase straight into a dark bedroom will lie there alert, because nothing has signalled to their body that sleep is coming. The bedtime was fine; the transition wasn't.

Most children need 30 to 45 minutes of progressively calmer activity: bath, pyjamas, teeth, a story, lights out — each step quieter than the last, in the same order every night. The order matters more than the contents, because a predictable sequence is itself the signal.

This is where bedtimes fall apart in practice. Each step stretches — a longer bath, one more story, a detour to find a particular toy — and a 40-minute routine becomes 70. Nobody decided that; it drifted. Giving each step its own visible countdown is what stops the drift, and it removes the negotiation too: when the story timer ends, there is no arguing about whether there's time for one more. Our bedtime routine timer guide covers the step-by-step setup, and the bedtime timer page has the short version.

Adjusting for Your Own Child

The chart gives you a starting point. Your child gives you the real answer, and there are three signals worth reading:

Waking naturally before the alarm, consistently and in a good mood, usually means they're getting enough. You can leave it alone.

Hard to wake, groggy, irritable for the first hour — that's a shortfall. Move the wind-down 15 minutes earlier and hold it for a week before judging.

Lying awake for an hour at a bedtime the chart says is right often means the bedtime is too early for that child. Pushing it earlier makes it worse. This is the counter-intuitive one most charts never mention.

Adjust in 15-minute steps, and give each change at least a week. Sleep patterns shift slowly, and a single bad night tells you nothing.

Naps, Teenagers and Other Complications

Naps count toward the total, which is why a toddler who napped until 4pm won't be asleep at 7pm. When a nap starts pushing bedtime late, cap it or move it earlier rather than fighting the bedtime — see the nap time timer guide. When naps end altogether, quiet time usefully replaces them.

Teenagers genuinely shift later. Adolescent body clocks move by an hour or more, so a 13-year-old who can't sleep at 9pm isn't being difficult — the biology really has changed. With school start times fixed, many teenagers simply can't get their 8 to 10 hours on a school night, which is a scheduling problem rather than a discipline one.

Weekends undo the work. A two-hour lie-in shifts the body clock enough to make Monday miserable. Keeping weekend wake-up within about an hour of the school-day time costs you a little on Saturday and saves the whole week.

Making a Bedtime Hold

1. Fix the wake-up time first — it anchors everything else.
2. Do the subtraction and write down the wind-down start, not just lights out.
3. Keep the same sequence every night. Predictability is most of the effect.
4. Time each step so the routine can't quietly stretch — this is where a visible countdown earns its place.
5. No screens in the final hour if you change only one thing; see screen time by age.
6. Adjust by 15 minutes at a time, and give each change a week.

Use a countdown your child can see rather than a clock. A seven-year-old can't usefully act on "it's 8.25, you have five minutes" — but they can see an arc that's nearly gone, which is the difference between a warning they can use and one they can't. Time blindness explains why that gap is so much wider than adults expect.

Frequently Asked Questions

What time should a child go to bed?

There is no single correct time. Work backwards from when your child has to wake up, subtracting the sleep their age needs and adding about 20 minutes for falling asleep. A six-year-old needing 10 hours who wakes at 7am should be asleep by 9pm, which means lights out around 8.40pm and the wind-down starting around 8pm.

How much sleep does a child need by age?

Widely used consensus ranges are 12 to 16 hours for infants aged 4 to 12 months including naps, 11 to 14 hours for ages 1 to 2, 10 to 13 hours for ages 3 to 5, 9 to 12 hours for ages 6 to 12, and 8 to 10 hours for teenagers. These are ranges rather than targets, and children vary within them.

Why does my child take so long to fall asleep?

Usually the wind-down is too short or too stimulating rather than the bedtime being wrong. A child who goes from a screen or active play straight to lights out is still alert when the lights go off. Most children need 30 to 45 minutes of progressively calmer activity, run in the same order each night, before sleep arrives easily.