This article attempts to estimate the time cost of children in France for couples who do not forgo any income, on the basis of the INSEE 1998-1999 time use survey. Having a child involves an increase in domestic work and/or the dedication of occupational income to pay for childcare. The reduction in "time for oneself"--leisure and personal care, i.e. 24 h less working hours paid or unpaid--is modelled for a dual-earner couple in full-time employment who do not use childcare services to increase his/her leisure time. Taking a couple in full-time employment avoids income endogeneity bias, since income is reduced by career interruption and part-time employment. These estimates account for this selection by full-time paid work. The article shows that time cost is roughly 1 h 30 min a day for a child aged 3-14, and is 4 h a day for each younger child. As this cost rises, the more fathers sacrifice some of their free time. The father and mother of two young children with a childminder thus each have only 11 hours of free time (including sleep) per day. The time cost of a large family (3 children) is equivalent to a full-time job on the labour market. In France, work-life balance policies and family pension entitlements only cover a small part of this cost.