Coffee you love.
Sleep you need.
Most advice treats them as enemies. We think they've just been badly introduced. JavaSleep is a slow magazine about the hours between your last sip and your first dream — with honest reviews, quiet science, and one very useful calculator.
How much caffeine
will still be awake
at your bedtime?
Caffeine doesn't clock out when you do. It has a half-life of about five hours, which means your 3 PM latte is still at half strength when you're trying to fall asleep at 11. Here's the honest math.
Adjust the inputs above to see your personal timeline.
Three things worth reading slowly.
Best Travel CPAP Machines (2026): AirMini vs. Transcend Micro vs. Z2 Auto
The best travel CPAP machine for most people is still the ResMed AirMini — if you can tolerate its waterless humidification and proprietary tubing.
Sleep Hygiene, Taken Literally: How Often Do You Actually Have to Wash Your Sheets?
The number gets recycled every summer: the average person washes their sheets every 24 days. It comes from a mattress-brand survey, not a laboratory, and it has mostly been doing work it was never…
One Late Espresso, Four Dashboards: What the TrainingPeaks Acquisition Reveals About Garmin Ecosystem Strategy
At 16:10 on a Tuesday I pulled a double — 18 g in, 36 g out, somewhere near 170 mg by the roaster's own stated figure — and then spent the night as an unpaid test subject for Garmin ecosystem…
“The most civilized thing a person can do is enjoy a cup of coffee at ten in the morning and still sleep at ten at night.— Editor's Note, Issue №001