Sleep debt tracker
Sleep debt calculator
Sleep debt accumulates quietly. The dangerous part is that you stop noticing the impairment well before the impairment stops. Enter your last 7 nights, set your personal target, and see where you actually stand.
Hours slept (last 7 nights)
Nightly sleep vs. target
Cumulative deficit is high enough to measurably degrade reaction time, mood, and decision-making — even if you feel fine. Plan a recovery week.
How debt is calculated
For each night where you slept less than your target, the difference adds to your debt. Nights above target don't bank credit — research (Van Dongen et al., Sleep 2003) shows surplus sleep doesn't store the way deficit does. The "days to recover" figure assumes you can add up to 2 extra hours per night before the body resists; chronic large debts pay down slower than that in practice.
The harshest finding in the literature: after two weeks of 6 hours per night, participants in the Van Dongen study performed as poorly as people fully sleep-deprived for two consecutive nights — but they consistently rated themselves as only "a little tired." Don't trust your subjective sense of recovery. Trust the math.
Sources: Van Dongen et al., Sleep 2003· CDC sleep recommendations· Depner et al., Curr Biol 2019 (weekend recovery limits)