How the count works
The UN gives the population of Japan on 1 January of each year, plus the births, deaths and migration it expects during the year. This page moves in a straight line from one 1 January to the next, so the number changes at the same pace all year. Born today and died today spread the year's births and deaths evenly over the seconds since midnight in your time zone.
It is an estimate, not a head count. Countries count their people in censuses and registers, and the UN builds these figures from those sources and from surveys.
Source: UN DESA, Population Division, World Population Prospects 2024 (medium variant), licensed under CC BY 3.0 IGO. Livecounts.nl turns the yearly figures into a per-second estimate; the UN has not reviewed this page.