Transparent calculator · Sleep 1.1
7-Day Sleep Shortfall Planner
Summarise a complete or partial seven-night sleep log. Unknown nights stay unknown; averages use recorded nights only.
Purpose
What this tool is for
Use this as a simple sleep-log summary, not as a biological “debt repayment” calculator.
Audience
Who it is for
Adults who want to review a week of sleep opportunity and identify a practical routine change.
Input glossary
What each field means
| Input | Unit or choice | Why it matters |
|---|---|---|
| Target | hours/night | Your planning reference; most adults are advised to sleep at least seven hours regularly. |
| Seven nights | hours | Keep seven calendar slots in order. Leave an unrecorded night blank or mark it unknown. Enter zero only for a recorded night with no sleep, never for missing data. |
| Severe sleepiness | yes/no | Adds an urgent do-not-drive message; it does not triage symptoms. |
Method · Sleep 1.1
The formula or decision logic
Nightly shortfall = max(0, target − slept). Longer nights are reported separately and never subtracted from the shortfall.
Coverage = recorded nights out of seven. Average = sum of recorded hours ÷ recorded nights. Unknown nights are excluded, not counted as zero, estimated or scaled up to a full week.
For a partial log, below/above-target totals cover recorded nights only. They are not a full-week shortfall. At least one recorded night is required.
The three-night comparison needs all of nights 1–3 and 5–7. It is unavailable if any of those six slots is unknown; an unknown night 4 does not enter either group. A difference of at least +0.25 hour is labelled up, at most −0.25 down, and strictly between these values roughly steady. This band is a Nutrinaut display heuristic, not a recovery measure.
References support the method or context; they do not validate an individual result. See the sources.
Worked example
Two illustrative examples, not real sleep records
- Complete example: target 8 hours; recorded nights 6, 6.5, 7, 7.5, 7.5, 8 and 8 hours.
- Average: 50.5 ÷ 7 = 7.21 hours. Total shortfall: 2 + 1.5 + 1 + 0.5 + 0.5 = 5.5 hours.
- Mean nights 5–7 minus mean nights 1–3 = 7.83 − 6.5 = +1.33 hours.
- Partial example: target 8 hours; seven slots 7, unknown, 8, 6, unknown, 8 and 7. Five recorded nights total 36 hours: 36 ÷ 5 = 7.2 hours/night.
- For the partial example, 1 + 0 + 2 + 0 + 1 = 4 hours below target across five recorded nights. This is not a weekly total. The three-night comparison is unavailable because nights 2 and 5 are unknown.
Interactive calculator
Summarise your recorded nights
Nothing you enter is sent to our server. Calculation happens in this browser.
Limitations
What the result cannot tell you
- Consumer estimates of sleep time can be inaccurate.
- Recorded nights may differ from missing nights. A partial-log average does not establish your average for the whole week.
- Extra sleep does not erase prior shortfall hour-for-hour.
- A trend does not prove recovery, readiness or safe alertness.
- Sleep-hygiene suggestions are not treatment for chronic insomnia.
Questions specific to this tool
Frequently asked questions
My watch missed a night. Should I enter zero?
No. Leave it blank or mark that night unknown. Zero means a recorded night with no sleep and would count toward the average and shortfall. Missing data are excluded, never filled with zero.
Can I use the result with fewer than seven nights?
Yes, with at least one recorded night. Coverage, the average and below/above-target totals are labelled for recorded nights only. No weekly total is estimated. The three-night comparison appears only when nights 1–3 and 5–7 are all recorded.
Is “sleep debt” a real bank balance?
No. The tool uses descriptive arithmetic. Biology does not repay an exact number of lost hours one-for-one.
What target should I choose?
At least seven hours is the adult consensus floor, while individual need varies. A clinician can help when sleep is persistently unrefreshing.
Can I catch up at the weekend?
Longer sleep may help how you feel, but it should not be treated as guaranteed reversal of every effect of insufficient sleep.
Does an upward trend mean I am recovered?
No. It only means calendar slots 5–7 averaged at least 0.25 hour longer than slots 1–3, with all six slots recorded. It does not measure recovery or safe alertness.
When should I seek help?
Persistent insomnia, severe daytime sleepiness, loud snoring or gasping, or drowsiness that affects safety warrant professional assessment.
Evidence and official references
Sources
Recommended amount of sleep for a healthy adult
American Academy of Sleep Medicine and Sleep Research Society · 2015
Supports: Adult sleep-duration consensusSleep and heart-healthy living
National Heart, Lung, and Blood Institute · Current
Supports: Adult 7–9-hour public guidanceFound a numerical or source issue? Send a correction with the page URL.
Apply the method
Before you trust a wearable trend
Check source, coverage and missing nights before you compare sleep numbers.
Read Eugene Blago’s field noteRead the latest field note
One night, two dates
Midnight, travel and clock changes can shift a sleep record’s date label. Check the interval and coverage before filling this log.
Read Eugene Blago’s field note