This study explores family formation–work fit (i.e., beliefs that work demands fit with desired family size) and its relation to achievement of desired family size, work–family facilitation and conflict, and marital satisfaction using a subsample (N = 690) drawn from the nationally representative Singapore National Study of Work–Life Harmony. Results indicate that family formation–work fit was positively related to desired family size achievement. Importantly, those with desired family size achievement had more than twice as many children as those who had not achieved their desired family size. In addition, workplace schedule flexibility, work-to-family facilitation, and marital satisfaction were associated with higher family formation–work fit, while family-to-work conflict and work-to-family conflict were associated with lower family formation–work fit. These findings indicate the importance of considering family formation–work fit when studying family fertility decisions, particularly in nations with low fertility rates.