Free tools
Sleep tools
Small tools that each do one useful thing. They run in your browser, they don't need an account, and they show you the result before asking anything of you.
How we build these
Sleep is a field with an unusually wide gap between what the evidence says and what the internet says. Plenty of sleep "calculators" work backwards from a fixed assumption — 90-minute cycles, eight hours, a single right bedtime for everyone — and hand back a confident answer that has no particular relationship to you.
Ours compute from what you actually enter, using the definitions clinicians use. Sleep efficiency here is the same quantity a sleep physician derives from a paper diary: total sleep divided by total time in bed, with time to fall asleep and time awake in the night both subtracted properly. Where your entries don't add up, the tool tells you which one to check instead of quietly producing a wrong figure.
The other half is knowing when a tool should stop talking. The intervention that low sleep efficiency points towards — compressing your time in bed — has strong evidence behind it and is genuinely not for everyone. It is the wrong answer for untreated sleep apnoea, and it needs clinical supervision in bipolar disorder and epilepsy, among others. So our calculator asks a short screen first, and where the answers point elsewhere it gives you your numbers and explains why it is not going to give you a schedule.
None of this is medical advice, and none of it replaces a doctor. Chronic insomnia — three nights a week for three months or more — deserves a proper conversation, and the first-line recommendation for it is therapy rather than medication.