Slaap berekenen

De slaapcalculator bepaalt de ideale slaaptijd of wektijd op basis van 90-minutige slaapcycli. Wakker worden midden in een slaapcyclus veroorzaakt slaperigheid en vermoeidheid overdag. Onze tool berekent de optimale momenten om naar bed te gaan of op te staan voor maximale energie.

Slaapkwaliteit hangt nauw samen met hydratatie. Gebruik ook onze Water Intake Calculator en onze Caloriebehoefte Calculator voor een volledig welzijnsoverzicht.

What is a sleep cycle and why does it matter?

Sleep consists of repeating cycles approximately 90 minutes long, each containing four stages: three stages of Non-REM sleep (light sleep, deeper sleep, and slow-wave deep sleep) and one stage of REM (Rapid Eye Movement) sleep. A complete night of 7–9 hours typically involves 5–6 full cycles. The critical insight: waking up in the middle of a cycle — especially during deep slow-wave sleep — causes sleep inertia, the groggy, disoriented feeling that can persist for 30–60 minutes. Waking up at the natural end of a cycle, when sleep is lightest, allows you to feel alert immediately. This is why our calculator recommends bedtimes that align with cycle completion rather than simply subtracting 8 hours from your alarm time.

Sleep debt and its real effects

Losing even 90 minutes of sleep per night (one cycle) for a week measurably impairs alertness, reaction time and cognitive performance to a degree equivalent to 24 hours of total sleep deprivation. The CDC considers insufficient sleep a public health epidemic, with 1 in 3 adults in developed countries failing to get the recommended 7–9 hours. For professionals managing their schedule, pair our sleep calculator with the Work Hours Calculator to ensure your productive hours are actually backed by restorative rest.