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About this tool
Add up your weekly sleep shortfall and spread the recovery across several nights instead of one long weekend lie-in.
Sleep debt is the running total of the hours you slept less than you needed, and this planner works it out from a week of nightly figures then splits the payback into small nightly instalments. It sums max(0, target hours - hours slept) for every night, caps the extra sleep added to any single night at two hours, and prints the earlier bedtime that produces it while your wake-up time stays fixed. It is built for shift workers, students and parents who want a realistic catch-up schedule rather than a Sunday lie-in.
Open Sleep Debt Payback Planner on AltFTool — it loads instantly in your browser.
Under "Your week" enter hours slept for each of the seven nights, from "Monday night (hours slept)" through "Sunday night (hours slept)".
In "Recovery settings" set "Nightly sleep target (hours)", a "Fixed wake-up time", "Extra sleep per recovery night (hours)" between 0.25 and 2, and "Recovery nights available" from 1 to 30.
"Total sleep debt" sums every night's shortfall against the target, and "Night-by-night payback" lists each recovery night's Asleep by time, Sleep and Debt left, alongside "Debt cleared by this plan" and "Debt still outstanding". "Copy result" copies the plan.
Surplus sleep on one night is reported separately, never silently subtracted from another night's shortfall.
Every recovery night shows the exact clock time to be asleep by, derived from your fixed wake-up time.
Extra sleep is capped at two hours a night so recovery does not turn into weekend social jet lag.
Sleep debt is the sum of each night's shortfall: for every night you add max(0, target hours - hours slept), and nights where you slept more than your target add nothing. Seven nights at 6.5 hours against an 8-hour target give 10.5 hours of debt.
Not fully. A single long night restores some alertness but studies of recovery sleep show attention and metabolic measures still lag after one weekend, and shifting your wake time by more than about two hours moves your circadian clock, which is why this planner spreads the payback over several nights instead.
Between 30 and 60 minutes is the instalment most people can hold to, and the planner caps any single night at two hours extra. Going to bed 45 minutes earlier for a week repays roughly 5 hours of debt without changing your wake-up time.
Adults aged 18 to 64 need 7 to 9 hours a night according to the American Academy of Sleep Medicine and Sleep Research Society consensus, with 7 hours as the lower bound for regular health. Use your own steady-state figure as the target if you know it; persistent sleepiness despite adequate hours is worth raising with a doctor.