About this site
Last reviewed: 14 September 2026
A free sleep calculator and a set of guides that try to explain the reasoning, not just hand you a time.
The Perfect Sleep Calculator is a free sleep timing tool and a set of plain-English guides to how sleep actually works. It is run by Nouvelle Digital, a small independent publisher based in the United Kingdom.
Why the site exists
Most sleep advice online has one of two problems. Either it is a bare calculator with no explanation of what the numbers mean, or it is an article that repeats the same six tips without ever saying which of them matters most.
We try to do both properly: give you the time, and explain the reasoning well enough that you can judge it for yourself — including where the science is genuinely uncertain.
How we write these pages
- Guidelines come from named sources. Sleep duration recommendations are taken from the American Academy of Sleep Medicine and the National Sleep Foundation. UK health guidance comes from the NHS. Every page says at the bottom which sources it used.
- We separate strong evidence from weak. Where something is popular but thinly supported — the military sleep method, say, or supplements that claim to raise deep sleep — we say so rather than repeating the claim.
- We say when a number is an estimate. The 90-minute sleep cycle is an average, real cycles run from about 70 to 120 minutes, and consumer sleep trackers estimate stages rather than measuring them. Those caveats belong next to the figures, not buried.
- Pages are dated and revised. Each one carries the date it was last reviewed.
What this site is not
It is not a medical service, and nothing here is medical advice. We do not diagnose, we do not recommend medicines or doses, and we are not a substitute for a doctor. Several of the guides exist partly to point people towards a GP — persistent tiredness, snoring with pauses in breathing, and insomnia lasting months all deserve a professional opinion rather than a website.
If you have a persistent sleep problem, please speak to your GP or doctor.
Your data
The calculator does its maths entirely in your browser. The time you enter is never sent to us or to anyone else. The full detail is in our Privacy Policy and Cookie Policy.
How the site is funded
Advertising, served by Google AdSense. We do not sell products, take sponsorship, or use affiliate links, so nothing on the site is written to sell you anything. Ads are clearly distinguishable from the content around them.
Getting in touch
Corrections are genuinely welcome — if something here is wrong or out of date, we want to know. Email nouvelledigitaladmin@gmail.com or see the contact page.