Japan's population is expected to fall to less than 90 million by 2055, compared with today's roughly 127.8 million, the Ministry of Health, Labor and Welfare said Wednesday.

The forecast is based on an estimate by the National Institute of Population and Social Security Research, an affiliate of the ministry, which made the projection on the assumption that the average Japanese woman will give birth to 1.26 children during her lifetime -- the fertility rate in 2005.

In an earlier population forecast in January 2002, the institute estimated the fertility rate would recover to 1.39.