Praktické

Kalkulačka spánku

😴Sleep Calculator — Optimal Bedtime

Wake-up time

What is Sleep Calculator?

▾

A sleep calculator determines the best bedtime or wake-up time based on 90-minute sleep cycles. Waking in the middle of a deep sleep stage causes grogginess (sleep inertia), while waking between cycles feels natural and refreshing.

DigiCalcs delivers precision-engineered tools for engineers and STEM professionals.

Vzorec

▾

f(x)Average sleep cycle = 90 minutes (can range 80–120 min)

How to Sleep Calculator

▾

1Average sleep cycle = 90 minutes (can range 80–120 min)
2Average time to fall asleep = 14 minutes
3Bedtime = Wake time − (cycles × 90 min) − 14 min
45–6 cycles = 7.5–9 hours — the recommended range for adults
54 cycles (6 hours) is the minimum to maintain cognitive function

Worked Examples

▾

Example 1

Given:Wake at 7:00am, 6 cycles

Výsledok:Bedtime: 9:46pm

6 × 90 min + 14 min = 554 min before 7am

Example 2

Given:Wake at 6:30am, 5 cycles

Výsledok:Bedtime: 10:16pm

Real-World Applications

▾

🏗️

Secondary and university physics/chemistry coursework

🔬

Laboratory calculations and experimental data analysis

📊

Engineering design and materials science applications

Sleep Requirements by Age (NHS / NSF)

▾

Age Group	Recommended Sleep	Notes
Newborn (0–3 mo)	14–17 hours	Multiple naps
Infant (4–11 mo)	12–15 hours	Including naps
Toddler (1–2 yr)	11–14 hours	Including naps
School age (6–13)	9–11 hours
Teen (14–17)	8–10 hours	Often sleep-deprived
Adult (18–64)	7–9 hours	Most important range
Older adult (65+)	7–8 hours	Earlier wake time common

Frequently Asked Questions

▾

What is Sleep?

The sleep calculator uses the science of sleep cycles to recommend optimal bedtimes. During sleep the brain cycles through stages roughly every 90 minutes: light sleep, deep sleep (slow-wave), and REM (Rapid Eye Movement)

How accurate is the Sleep calculator?

The calculator uses the standard published formula for sleep. Results are accurate to the precision of the inputs you provide. For financial, medical, or legal decisions, always verify with a qualified professional.

What units does the Sleep calculator use?

This calculator works with inches, watts. You can enter values in the units shown — the calculator handles all conversions internally.

What formula does the Sleep calculator use?

The core formula is: Average sleep cycle = 90 minutes (can range 80–120 min). Each step in the calculation is shown so you can verify the result manually.

💡

Pro Tip

Even a 20-minute "power nap" between 1–3 PM can restore alertness without disrupting nighttime sleep. Longer naps (>30 min) risk sleep inertia and disrupted night sleep.

⭐

Did you know?

REM sleep lengthens in later cycles — your first REM stage is about 10 minutes; the last (before waking) can be 60 minutes. This is why you often remember dreams from the morning.

References

Môžete tiež potrebovať

→

Dice Roller

→

Lottery Number Generator

→

Bingo Number Generator

→

Poker Calculator

Accuracy-checked

Reviewed October 2026

Our methodology

Získajte týždenné matematické tipy

Pridajte sa k 12 000+ odberateľom, ktorí každý týždeň dostávajú tipy na kalkulačku.

🔒

100% zadarmo

Nikdy bez registrácie

✓

Presné

Overené vzorce

⚡

Okamžité

Výsledky počas písania

📱

Vhodné pre mobily

Všetky zariadenia