Free U.S. shipping on orders $35+ · Subscribe & save
TOOLS
Calculators for caffeine, sleep and attention, plus two reference tools for nicotine pouches. They run in your browser, they ask for no email, and nothing you type is sent anywhere or stored. Where a number comes from a study, the study is named on the page, along with how many people were in it. Where it comes from a manufacturer, the page links to it.
Caffeine Calculator: Half-Life, Daily Budget and Bedtime
Work out how much caffeine is still in you, how close to bedtime your last dose can land, and what a day adds up to. Ranges, not false precision.
Brain Fog or Just Tired? A Five-Question Check
Five questions that separate brain fog from ordinary sleepiness and from the early-afternoon dip, with what each answer actually points at.
Sleep Debt Calculator
Add up two weeks of nights, see the debt in hours, and get a repayment estimate based on what the recovery studies actually measured.
Attention Span Test: Five Timed Minutes
A timed test that measures seconds on task before you switch, which is what the research actually counts, plus a seven-day log to retest against.
Caffeine Sensitivity Check
Seven questions using the behavioural markers that track with fast and slow caffeine metabolism, and a milligram ladder to test against. No DNA kit.
Caffeine-Timed Workday Builder
Put your wake time, bedtime and chronotype in, get an hour-by-hour day back with a dose lane, the predicted dip, and the hour your last dose has to land.
Jet Lag Calculator: Light and Caffeine Windows
Direction-weighted recovery days for your flight, plus the hours to seek and avoid light and the hour to stop caffeine on arrival day.
Nicotine Pouch to Cigarette Calculator
Pick a pouch strength and how many you use a day, get a cigarette-equivalent nicotine range, with every assumption and its study shown.
Nicotine Pouch Strength Chart by Brand
Milligrams per pouch and pouches per can for ZYN, on!, Rogue, ALP and Lucy, copied from each maker's own site, with a source link and date on every row.
None of these is medical advice and none of them diagnoses anything. They are arithmetic and published averages applied to numbers you type in, which means they describe a typical person rather than you specifically. If something about your sleep or your energy has been wrong for weeks, that is worth raising with a clinician rather than a calculator.