Bedtime Calculator

This calculator uses the National Sleep Foundation (NSF) recommended sleep durations, which are grouped by age. For each age it gives a healthy range of total sleep per 24 hours, along with a recommended midpoint.

• Bedtime window: your bedtimes are simply the wake-up time minus the recommended sleep. Sleeping longer means an earlier bedtime, so the "earliest bedtime" corresponds to the maximum recommended sleep and the "latest" to the minimum.
• Ideal bedtime: uses the midpoint of the recommended range — a good default target for a consistent routine.
• Naps: for babies, toddlers, and preschoolers the NSF totals include daytime naps. If your child naps, their overnight sleep need is lower, so nudge bedtime a little later than the earliest value shown.
• Sleep cycles: people sleep in repeating cycles of light sleep, deep sleep, and REM. Cycles are shorter in babies (about 50 minutes) and lengthen toward the adult ~90 minutes by school age. Waking at the end of a cycle feels more natural than being roused mid-cycle.

These are general guidelines, not medical advice. Every child is different; a consistent routine and your child's own alertness matter more than hitting an exact minute. Discuss ongoing sleep concerns with your pediatrician.

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