Daily How Much

For health, most adults need 7–9 hours of sleep nightly; children and teens need more based on age.

Yes, even a small block of sleep beats an all-nighter for alertness, though crash-risk tasks still demand full rest.

When you’re sick, aim for normal age-based sleep—adults 7–9 hours nightly—with extra rest or naps as needed in the first few days.

For third trimester sleep, most pregnant adults need 7–9 nightly hours, often with a short daytime nap.

In the first trimester, aim for 7–9 hours of nightly sleep plus short daytime naps to meet pregnancy sleep needs.

Aim for 7–9 hours of nightly sleep in the first trimester, with short daytime naps when fatigue from early pregnancy makes nights feel short.

New mothers do best with 7–9 hours in 24 hours, aiming for one 4–6-hour core block plus naps while the baby’s night feeds keep sleep fragmented.

Most students perform best with 7–9 hours before an exam, planned across prior nights and kept on a steady schedule.

Adults typically get about 50% N2, 15–25% N3, and 20–25% REM across 7–9 hours, repeating in roughly 90-minute cycles.

For healthy adults, light sleep (N1+N2) usually totals about half your night—aim for 7–9 hours of sleep and let the mix self-balance.