In absence of such, estimates of "residual volume" have been prepared as a proportion of body mass for infants (18.1 mL/kg), or as a proportion of "vital capacity" (0.24 for men and 0.28 for women) or in relation to height and age ((0.0275* Age [cm-2.6139) litres for normal-mass individuals and (0.0277*Age [cm-2.3967) litres for overweight individuals).