About SleepCalcs

SleepCalcs is a collection of free sleep calculators, quizzes, planners and checklists. It is run by a small independent publisher that builds simple online tools that are free to use. There is no account to create and nothing to install.

What the site is for

Most people only think about sleep when they are short of it. The tools here help you plan ahead with practical questions such as:

The tools are grouped into timing calculators, recovery and health tools, personal and lifestyle tools, and guides for specific groups such as students, shift workers and parents of kids.

How the tools are designed

Each tool does one job and shows its result right away. Many of the timing tools use a simple model: a sleep cycle of about 90 minutes, plus a few minutes to fall asleep. This is an average, and your own cycles may be shorter or longer.

Here is an example. If you must wake up at 7:00 and want 5 cycles, you need 5 × 90 minutes = 7 hours 30 minutes of sleep. Add about 15 minutes to fall asleep, and the suggested bedtime is 23:15.

How we check our work

What the tools are not

SleepCalcs gives general information and estimates. It does not provide medical advice, and it cannot diagnose or treat any condition. If you have ongoing trouble sleeping, feel very tired during the day, or have health concerns, please speak with a qualified health professional.

How the site is funded

The site is free for visitors. It is supported by advertising, and we use audience measurement to understand which tools are useful and where the site can improve. You can find the details in our privacy policy.

Contact us

Found a bug, have an idea for a new tool, or spotted something that looks wrong? Write to us at thefreecollection@gmail.com. We read every message and reply as soon as we reasonably can.

Frequently Asked Questions

Yes. Every tool on SleepCalcs is free to use with no account required. We support the site through unobtrusive ads, never by selling data or pushing subscriptions.
Sleepyti.me was one of the original sleep calculators but became heavily ad-focused after being sold in 2019. SleepCalcs offers a broader toolkit (20 tools vs 1), cleaner design, and keeps ads minimal and non-intrusive.
No. Every tool works directly in your browser on any device. Nothing to install.
Our calculators use established sleep science (90-minute cycles, chronotype research, circadian principles). They provide general guidance, not medical advice. If you have a sleep disorder, please see a qualified healthcare provider.
Research shows human sleep cycles average 90 minutes, moving through light sleep, deep sleep, and REM. Waking at the end of a full cycle (rather than mid-cycle) generally feels less groggy. Our calculators time your wake-up to these cycle endings.
We use standard web analytics (Google Analytics) to understand site usage, but we do not store, sell, or share personal sleep data. All calculations happen in your browser.