Sleep Diary

A sleep diary is the cheapest useful thing you can do about bad sleep. One rough night tells you nothing. Two weeks of honest notes will usually show you a pattern — the wine, the 4pm coffee, the room that is fine in June and impossible in January — that no single night could. And if you do end up speaking to a GP or a sleep clinic, a filled-in diary is the first thing they will ask for.

The diary is on this page rather than a file to download, because the version you will actually fill in is the one sitting by the bed. Print this page, or copy the two short lists into a notebook.

Each morning, before you do anything else

Write these down while you still remember them. Guesses are fine — do not lie awake checking the clock, because that makes the thing you are measuring worse.

  • What time you got into bed, and what time you think you fell asleep
  • How many times you woke, and roughly how long you were awake
  • What time you woke for the last time, and what time you got up
  • How you feel out of ten, before coffee
  • Anything that woke you: noise, light, heat, a partner, a child, your own head
  • Any dreams worth remembering

Each evening, before bed

  • Caffeine: what, and what time you finished
  • Alcohol: what, and what time you finished
  • Exercise: what, and what time
  • Naps: when, and how long
  • When the screens went off
  • The room: dark, quiet and cool enough? Mark each one yes or no
  • How wound up you are out of ten

After two weeks, look for these

You are not looking for a bad night. You are looking for the thing that keeps turning up next to bad nights.

  • Falling asleep or staying asleep? They have different answers, and most people assume they have the first problem when the diary says otherwise.
  • Does your bedtime move around? An inconsistent wake time disrupts sleep more reliably than an inconsistent bedtime.
  • How late is the last coffee? Caffeine has a long tail, and afternoon is later than most people think.
  • Does alcohol show up next to your broken nights? It usually shortens the time to fall asleep and wrecks the second half.
  • Is it the room or is it you? If light, heat and noise keep appearing in the woke-me column, the fix is the room, and it is a cheaper fix than most.

When to stop keeping a diary

Two to four weeks is plenty. A sleep diary is a measuring tool, and past a certain point measuring your sleep every night becomes another thing to be anxious about at 3am. Fill it in, find the pattern, act on it, and put it away.

Once you know the pattern

The Sleep Calculator takes the same questions your diary has just answered — falling asleep or staying asleep, whether the room is noisy, bright or warm, when the screens go off — and builds a timed wind-down routine around them. It will tell you when the answer is a change to the room rather than something to buy.

A sleep diary and this calculator are wellness tools, not medical advice. If your sleep is a health concern, or if the diary turns up something that worries you, please speak to your GP.