This article proposes an `equivalence scale for time by whichinformation about total working time in both paid and unpaid labour canbe derived just from information about paid working time and householdstructure. Different scales are offered for males and females, and anadjustment according to year is also provided. These proposal is basedon highly significant and robust OLS analyses of time-use surveysinvolving 99,137 respondents from 28 surveys in 13 western countries.