Most owners can report that their cat sleeps a lot and nothing else. A 24-hour sheet turns that into 96 blocks of 15 minutes and 4 numbers you can compare with a range before the next meal. Adult cats sleep 12-16 hours in 24; kittens under 4 months reach 18-20; cats past 11 years often sit at 16-18. The audit answers 1 question: is the total inside the band, and if not, which of 3 patterns moved it.
Print 1 page and fill it at 6 checkpoints instead of every quarter hour: 08:00, 11:00, 14:00, 17:00, 20:00 and 23:00. The blocks exist for reading the data, not for watching the clock.
Why 15 minutes is the right block size
A REM bout in a cat lasts 5-10 minutes and a full sleep cycle runs 20-30. A 15-minute block sits between the 2. It is long enough that a doze cannot hide inside it, and short enough that 96 of them fit on 1 page at 4 per row. Try 5-minute blocks and you get 288 entries, abandoned by day 2. Try 60-minute blocks and the wake-ups dissolve into the sleep, which deletes the most diagnostic number on the sheet.
4 columns, each scored in under 5 seconds
Column 1 is the block, 00:00 to 23:45, 96 of them. Column 2 is place, coded A, B or C for the 3 spots the cat actually uses; a fourth code D covers everywhere else and should stay under 10% of the day. Column 3 is posture: curled, side, belly-up, loaf. Column 4 is depth on a 1-3 scale: 1 for ears still tracking sound, 2 for eyes closed with a twitch response, 3 for limp and past responding to its name.
Two optional columns earn their space. Wake-up cause (noise, person, other cat, unknown) and room temperature. Take the temperature at 3 points, 08:00, 14:00 and 22:00: a 4-5 degree spread across the day is normal, 8 degrees is a draft or a sun trap.
What a normal 24 hours looks like
Fill the sheet first, then compare. The ranges below are the ones most vets accept without asking a second question, for an indoor cat aged 3-11 in a room held at 20-24 C.
| Block | Asleep (min) | Deep bouts | Wake-ups | What looks normal there |
|---|---|---|---|---|
| 00:00-06:00 | 300-330 | 4-6 | 1-3 | 2 long stretches, 1 toilet trip near 03:00 |
| 06:00-12:00 | 150-180 | 3-5 | 4-6 | 20-40 min of activity around 06:00-07:30 |
| 12:00-18:00 | 210-240 | 5-7 | 2-4 | deepest run 13:00-15:00, 2-3 postural shifts |
| 18:00-24:00 | 120-150 | 2-4 | 3-5 | 30-60 min of activity before the last meal |
Total the asleep column. Anything from 780 to 900 minutes, 13 to 15 hours, needs no explanation. A cat at 960 minutes (16 hours) is at the top of the band and is fine in a 16 C room in winter. A cat at 660 minutes (11 hours) is under the band, and the question becomes where the missing 2-3 hours went.
3 patterns the totals reveal
Fragmentation: more than 8 wake-ups inside any 6-hour block, with no single stretch over 40 minutes. That pattern is the one most often tied to pain, a full bladder or a room that never gets dark, and it is the one worth a vet visit within 7 days.
Displacement: the cat sleeps in 1 of the 3 spots for over 80% of the total, or drops the warmest spot it used all last winter. Before reading anything into it, log temperature and noise for 3 days, since a 5-degree drop or a new appliance at 40-50 dB moves a cat with nothing else wrong. The environment audit sheet lists the 6 parameters worth measuring.
Inversion: over 60% of sleep in daylight and under 25% between 22:00 and 06:00. In a cat past 11 this is common and usually benign when the total is normal. In a cat under 5 with a normal total, work on the 18:00-22:00 window first, because 30-60 minutes of activity there restores most nights inside 14 days. The slower shift in sleep location that comes with age is a separate chart.
The 7-day version, when 1 day argues with itself
Run 7 consecutive sheets with the same pen and the same 6 checkpoints. Sum each day and plot 7 points: a 60-90 minute spread across the week is noise, a 180-minute trend over 7 days is a signal. Note weather and visitors in the margin, because a cat that loses 2 hours of sleep for 2 nights after guests is behaving normally, and a cat that loses 2 hours for 14 nights is not.
Breed sets the baseline, not the verdict. A Bengal at 12-13 hours and a Persian at 17-18 can both be healthy; what matters is that each cat stays on its own line. If you are unsure which baseline applies, the breed quiz narrows it in about 3 minutes.
When the sheet becomes a vet appointment
Book within 48 hours for: more than 18 hours of sleep a day for 7 days in an adult, 3 or more nights of vocalisation with under 30% of the night asleep, or rest breathing over 30 breaths a minute (count for 30 seconds, multiply by 2). Book within 7 days for: 8 or more wake-ups a night, sleep confined to 1 spot, or a 5% weight change in 30 days. None of these is a diagnosis; each is a reason to hand the sheet to someone who can examine the cat.
Do this tonight
- Draw the grid: 96 blocks, 4 columns, 1 page.
- Label the 3 sleeping spots A, B and C before the first entry.
- Set 6 alarms from 08:00 to 23:00, every 3 hours.
- Log temperature 3 times and count wake-ups per block.
- Total the asleep column at 23:45 and compare with 780-900 minutes.
One day of writing replaces a year of guessing, and the cost is 1 pen plus 15 minutes of attention spread over 24 hours. If the total lands inside the band and the 3 patterns are absent, you have a baseline for the next time something changes.
Frequently asked
How many hours a day should a cat sleep?
Adult cats run 12-16 hours in 24. Kittens under 4 months can reach 18-20, and cats past 11 years often sit at 16-18. What matters more than the total is the shape: 780-900 minutes split into long night stretches and 30-60 minute activity windows at dawn and dusk is the pattern most vets accept without further questions.
Why log sleep in 15-minute blocks?
A REM bout lasts 5-10 minutes and a full sleep cycle 20-30, so 15 minutes catches a doze without splitting it. Five-minute blocks produce 288 entries that get abandoned by day 2, and 60-minute blocks merge the wake-ups into the sleep, which removes the single most useful number on the sheet.
When does a sleep change mean a vet visit?
Go within 48 hours for over 18 hours of sleep a day for 7 days in an adult, 3 or more nights of vocalisation with under 30% of the night asleep, or rest breathing over 30 breaths a minute. Go within 7 days for 8 or more wake-ups a night, or a 5% weight change in 30 days.