Gezondheid

Sleep Calculator

How many complete sleep cycles will you get tonight? Enter your planned sleep hours and find the ideal duration to wake up feeling refreshed.

✓ Gecontroleerd door Julian Bronski · bijgewerkt juni 2026

Jouw gegevens

Planned sleep hours 7.5

312+

Resultaat

Complete sleep cycles

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Ideal sleep duration (h)

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Next cycle target (h)

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<iframe src="https://kalkulio.app/nl/sleep-calculator/embed/" style="width:100%;max-width:720px;height:505px;border:0;border-radius:16px;background:#faf9f4" title="Sleep Calculator" loading="lazy"></iframe>
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Zo werkt de Sleep Calculator

Human sleep occurs in cycles of 90 minutes each. Waking in the middle of a cycle leaves you groggy – it's best to wake after a complete number of cycles. Formula: cycles = ⌊hours × 60 ÷ 90⌋, ideal duration: cycles × 1.5 h.

Veelgestelde vragen

How long is a sleep cycle? ▾

A complete sleep cycle lasts about 90 minutes and includes light sleep, deep sleep and REM sleep. Most adults go through 4–6 cycles per night.

Why am I more tired after 8 hours than 7.5? ▾

You're probably waking in the middle of a cycle. 7.5 h (5 cycles) or 9 h (6 cycles) is better than exactly 8 h – try going to bed 15 minutes earlier.

What helps with falling asleep? ▾

Regular sleep times, darkness, a cool room (16–18°C) and no screens 30 minutes before bed are the most effective measures according to sleep research.

Geen financieel of medisch advies. Zonder garantie.

Zo werkt de Sleep Calculator

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