Sleep Debt Calculator
Add up the gap between the sleep you need and the sleep you actually got. Enter your nightly target and your last 7–14 nights to see your cumulative sleep debt and where it's trending.
How to use it
- Set your nightly sleep target in hours (for example, 8).
- Enter the hours you actually slept for each of the last 7–14 nights.
- Read your cumulative sleep debt, your nightly average deficit, and whether the trend is improving or worsening.
What is sleep debt?
Sleep debt is the running total of how far your actual sleep falls short of your own target, night after night. If you need 8 hours and sleep 6.5, that is 1.5 hours of debt for the night; the calculator sums these shortfalls across your recent nights.
For athletes, accumulated short sleep blunts recovery and readiness, so tracking the running deficit gives a simple, honest picture of whether recovery is keeping pace with training.
Can you catch up on sleep debt?
Short-term debt can be partly repaid with extra sleep over the following nights, which is why the trend matters more than any single night. Consistently hitting your target — rather than swinging between deprivation and long lie-ins — is the more reliable way to keep the balance near zero.
Frequently asked questions
How is sleep debt calculated?
Sleep debt is the sum of (nightly target − actual sleep) across your recent nights, counting only the nights you slept below target. This calculator also shows your net balance, which subtracts nights you slept over target.
How much sleep debt is too much?
There is no universal threshold — what matters is the trend. A debt that keeps growing week over week is a sign recovery isn't keeping pace with training load and life stress.
Educational, performance-oriented content for athletes — not medical advice. Thresholds and reference ranges come from group data and vary between individuals.