Fertility has declined in developed countries but whether there is a similar pattern in the number of children individuals wish to have (henceforth an ideal number of children) remains unclear. Using repeated cross-sectional survey data from the Finnish Family Barometers, we examine birth cohort changes in the ideal number of children among men and women from five birth cohorts (1970–1974, 1975–1979, 1980–1984, 1985–1989, and 1990–1994). We also investigate whether associations between socioeconomic factors and the ideal number of children differ across birth cohorts, and whether there are any gender differences in these associations. We find that the ideal number of children is lower among more recent than earlier birth cohorts and that this shift is driven by substantially higher child-free ideals among recent cohorts. While the ideal number of children among men and women is associated with socioeconomic factors, birth cohort differences remain significant after controlling for these characteristics. These findings suggest that large birth cohort differences in child-free ideals are not due to the individual socioeconomic circumstances of more recent birth cohorts. Rather, it appears that the childbearing attitudes of Finns have changed and may have contributed to the recent fertility decline.