Sibling nap sync calculator
Find out when both of your children will nap at the exact same time so you can get a guaranteed afternoon break.
How sibling nap syncing works
To achieve overlapping naps when managing two children under two, lock in your older toddler's afternoon nap time first. Then, adjust your infant's morning wake windows so their second or third nap aligns directly with the toddler's sleep schedule.
Why this tool exists and nothing else like it really does
Single-child wake-window calculators are common; a calculator built specifically to find the overlap between two different kids' nap schedules is not. That's the actual gap this tool fills — most parents end up running two separate calculators in different tabs and doing the overlap math by hand, which is exactly the annoying process this replaces.
When the calculator says there's no overlap
Not every age combination has a real overlap window — a newborn on 4–5 short naps a day and a toddler on one long afternoon nap sometimes genuinely don't line up, especially in the early weeks. If that's your result:
- Check back after the younger child's naps consolidate — this usually happens gradually between 3–9 months and creates overlap windows that didn't exist before.
- Aim for partial overlap rather than full sync — even a 20–30 minute shared window is worth protecting, even when the calculator can't find a full nap-length match.
- See the dueling naps schedule for the specific case of a baby on two naps paired with a toddler on one — it covers exactly this no-overlap stage in more depth than a calculator result can.
FAQ
Why does the tool ask for morning wake time for both kids, not just one?
Because the overlap window is driven by both kids' full wake-window math, not just one child's schedule — a 15-minute difference in either child's wake time can shift the overlap window meaningfully.
What if my kids' overlap window keeps drifting to a different time each day?
That's normal in the early weeks of any nap-consolidation stage (commonly 3–4 months and again around 9 months) — recalculate every few days during a transition rather than expecting a fixed daily time to hold.
Should I wake a sleeping child to force the overlap?
Generally no — forcing an early wake-up to chase a calculated overlap usually costs you more in overtiredness than the shared nap time is worth. Treat the calculator's output as a target to nudge toward gradually, not a hard rule for tonight.
Want the full daily picture, not just naptime?
This calculator solves the nap-overlap question. For a complete sample day — wake time, meals, and bedtime, not just naps — see the 2 under 2 schedule or two toddlers sync page, whichever matches your kids' ages.
Want automated schedule adjustments?
Track dynamic nap times live in the Sibling Stack app.
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