Calculator and results
Track Your Sleep Efficiency Over Time
Add each night’s time in bed and estimated time asleep. Compare your own nights without turning a single percentage into a diagnosis or a treatment plan.
Calculations stay in this page. Saving is optional and uses this browser’s local storage. Turning it off removes the saved copy. CSV export creates a file on your device. Notes may contain personal information; keep that file private.Your Recorded Nights
No nights recorded yet. Add a night to calculate its efficiency.
| Night ending | In bed | Asleep | Efficiency | Notes | Action |
|---|
How The Calculation Works
Formula
Where
- S
- Sum of estimated hours asleep across the recorded nights.
- B
- Sum of hours in bed across exactly the same nights.
- SEdiary
- The weighted diary percentage, not the average of nightly percentages.
Example
For a single-night calculation, use the sleep efficiency calculator. Compare actual duration with the sleep duration calculator. Read the insomnia guide for context.
Method context: AASM behavioral-treatment guideline. This diary performs arithmetic on your estimates; it does not implement clinician-led treatment.
How to record and correct a night
- Choose the morning date after the night you are recording.
- Enter time in bed and estimated time asleep in hours. Use 7.5 for 7 hours 30 minutes. Zero sleep is allowed, but sleep cannot exceed time in bed.
- Add an optional note, then choose Add or update night. Editing the form alone does not change a saved row.
Use the morning date for each night. To correct a row, choose its Edit button, change the inputs and submit. The same date is replaced, so a correction does not add a duplicate night.
How to read the diary results
The summary combines all recorded nights using their total sleep and time in bed. Each table row shows one night, so a long night contributes more to the combined ratio than a short one.
The chart appears after two dated nights. Its vertical scale runs from 0% to 100%, and its horizontal spacing follows the entered dates. The table gives the exact values. A line across a missing date does not represent a measured night.
Review sleep duration and notes alongside the percentage. A high ratio from a short night does not show that you slept enough.
Saving and exporting your sleep diary
Without saving, the diary stays only in this page session. Opting in saves it in this browser when storage works. Read the status message; blocked storage means you should export before closing. Reset inputs preserves the diary and saving choice. Clear removes the current records and attempts to update or remove the stored copy.
Export diary CSV downloads dates, durations, percentages and notes. It is not a backup that this tool can import: there is no CSV-import control. Keep exported notes private. Clearing browser data can remove a saved diary.
In an isolated embed, browser saving is disabled. You can still record nights during the open session and export CSV.
When the diary is not enough
This page performs arithmetic on estimates. It cannot identify sleep stages or determine why a pattern changed. It does not diagnose insomnia or generate a sleep-restriction schedule.
For sleep-diary context and recurring sleep problems, see CDC guidance on sleep and keeping a diary. You can bring your dated entries to a healthcare appointment.
Frequently asked questions
Why did the chart not appear after one entry?
The revised chart shows one point for a single entry. More entries add their own dated points. Lines join consecutive recorded dates only; a missing date is not zero sleep.
Can I leave time asleep blank for a sleepless night?
Enter zero explicitly. A blank field is treated as missing information.
Will adding the same date create another night?
No. The new values replace the existing row for that date.
Can I upload a CSV to restore my diary?
No. Export is available, but this tool does not provide CSV import. Keep a copy of important records outside the browser.
Using the controls and keeping a result
Use the plus and minus buttons beside an adjustable value, or type directly into the field. Numeric controls respect declared field limits; a combination of individually valid values may still fail the calculator’s consistency checks.
The plus and minus buttons edit the draft entry. Choose Add or update night to change the recorded diary.
- Print opens the tool interface and its current results for printing, without the guide or navigation.
- Share sends the public tool URL. It does not include entered values. When sharing is unavailable, the page offers copying or a visible link.
- Embed displays self-contained code for the tool. It starts with public defaults and excludes the guide and your current entries.