Free sleep tools
Small, fast calculators for planning a night’s sleep: when to go to bed, how long to nap, when to stop coffee and how much sleep you need. Each one explains the research behind it, and all of them run in your browser.
Plan your night
Sleep calculator
Pick a wake-up time and get bedtimes that line up with roughly 90-minute sleep cycles, or work forward from tonight.
Free toolNap calculator
Choose a 10, 20, 30 or 90 minute nap and get the exact time to set your alarm, with what the nap research found.
Free toolCaffeine cutoff calculator
When to have your last coffee for tonight’s bedtime, and roughly how much caffeine is still around when you lie down.
Free toolSleep debt calculator
Enter last week’s nights to see your shortfall against your sleep target, and a gentle way to make it up.
Free tool4-7-8 breathing exercise
A calm, on-screen pacer for 4-7-8, box breathing, cyclic sighing and slow breathing before bed.
Free toolHow much sleep do I need?
Enter an age to see the recommended hours of sleep from the National Sleep Foundation’s expert panel.
Pair a tool with a sound
Worked out your bedtime? Mask the noise around you with a steady sound. Start with the free in-browser sound player, browse every sleep sound, or read the setup guides.
Free sleep sound player
Play white, pink, brown and green noise, rain and a lofi beat in your browser, with a sleep timer.
SoundBrown noise for sleep
The deep, low rumble. What it is, why people like it, and how to use it all night.
SoundRain sounds for sleep
Soft rain, rain on a tent, tin roofs and window glass: which rain to pick and how to set it up.
GuideWhite vs pink vs brown noise
Listen to all four side by side, then use a three-night test to pick yours.
Questions
Are these sleep tools free?
Yes. Every tool on this page is free, needs no sign-up and runs in your web browser.
Do the tools save or send my information?
No. The calculations happen on your device. Nothing you type is stored or sent to us or anyone else.
Can a calculator tell me exactly when to sleep?
No. The tools are based on averages from published research, and real sleep varies from night to night and person to person. Use the results as a starting point and adjust to how you feel.
These tools give general estimates for healthy adults and are not medical advice. If you are often tired despite enough time in bed, or have ongoing trouble sleeping, talk to a doctor or a sleep specialist.