Sleep Debt Calculator
Estimate accumulated sleep shortfall from target sleep, actual sleep and number of days.
Inputs
Result
Total sleep debt
10.5 hr
1.5 hr short per night
Visual breakdown
Nightly shortfall
1.5 hr
Days
7
Total debt
10.5 hr
Cumulative
Equivalent nights
1.31
At target
Formula
Sleep debt = max(0, target − actual) × days. Surpluses don't subtract from past debt.
Example
8 hr target, 6.5 hr actual, 7 days → 1.5 × 7 = 10.5 hr debt.
Common examples
8 hr target, 6.5 hr actual, 7 days
1.5 hr/night · 10.5 hr total debt.
Two-week stretch
Small shortfalls add up across 14 days.
Catch-up plan
Spread recovery sleep over several nights.
Frequently asked
Can I 'pay off' sleep debt?
Partly. Modest debt usually recovers within a few nights of extra sleep. Long stretches of deprivation take longer.
Is one big weekend lie-in enough?
It helps somewhat but doesn't fully erase a week of short sleep. Consistent, slightly-longer nights work better.
Does the calculator account for sleep quality?
No — only duration. Fragmented or low-quality sleep can leave you tired even with debt at zero.
People also calculate
More health →Educational estimate only — not medical advice.