About Us

Chrona is a small set of sleep-planning tools built around one idea: timing sleep in whole cycles, not just hours, tends to produce easier wake-ups.

What Chrona is — and isn't

Chrona provides a bedtime and wake-up calculator, a nap calculator, a caffeine cutoff calculator, and a sleep debt tracker, alongside plain-language guides explaining the sleep science behind each one. Every tool is free, requires no account, and keeps your data in your browser rather than on a server.

Chrona is an educational planning resource, not a medical device or diagnostic tool. It doesn't replace the judgment of a doctor or sleep specialist, particularly for ongoing insomnia, sleep apnea, or other suspected sleep disorders.

Methodology

The calculators use a standard cycle-based model: a default 90-minute sleep cycle and a default 14-minute average time-to-fall-asleep, both drawn from commonly cited ranges in sleep research, and both adjustable in the calculator's settings since real cycle length and sleep latency vary by person. Results are computed entirely in your browser — no calculation is sent to or stored on a server.

The nap durations (20, 26, 60, and 90 minutes) and the caffeine half-life range (5–6 hours) reflect commonly cited figures in sleep-science literature and are explained in more depth on the relevant guide pages, with the reasoning behind each shown rather than presented as unexplained defaults.

Editorial process

Guide content is written in plain language, reviewed for accuracy against generally accepted sleep-science sources, and dated so you can see when it was last checked. If you spot something that looks outdated or incorrect, the contact page goes directly to the person maintaining the site.

Contact

Questions, corrections, or feedback: [email protected] or the contact form.