Sleep tools, science-backed
Sleep math, simplified.
Calculators, planners, and validated screeners for cycles, jet lag, naps, caffeine, debt, insomnia, apnea risk, and more — every recommendation traceable to peer-reviewed sources.
Daily tools
Tune today's sleep against today's variables.
Self-assessments
Validated screeners used in sleep research.
Chronotype quiz
10-question MEQ-style quiz: lark, third-bird, or owl?
Insomnia (ISI)
7-item Insomnia Severity Index validated screener.
Apnea risk (STOP-BANG)
8 yes/no questions screening obstructive sleep apnea.
Sleep efficiency
% of time in bed actually spent asleep — core CBT-I metric.
Sleep latency
Is your sleep onset time normal, fast, or prolonged?
Lifestyle & travel
Sleep across unusual schedules and time zones.
Jet lag planner
Multi-day plan for any city pair: light, melatonin, bedtime shifts.
Shift work guide
Sleep strategies for nurses, pilots, truckers, and night workers.
Polyphasic schedules
Everyman, Uberman, Dymaxion, and biphasic compared honestly.
Adult sleep by age
How much sleep adults need across decades, with sources.
Children's sleep
Schedules from newborn through teen — naps, windows, bedtimes.
Why a suite, not one tool
Most sleep calculators answer one question. The ones that matter to you change every week — you're jet-lagged on Monday, on a deadline sprint by Thursday, and figuring out whether a 20-minute nap will help or hurt by Friday afternoon. The same physiology drives them all, so the tools share data and logic, and link to each other where they should.