Working with shuffles, we establish a close link between Kendall’s
τ
\tau
, the so-called length measure, and the surface area of bivariate copulas and derive some consequences. While it is well known that Spearman’s
ρ
\rho
of a bivariate copula
A
A
is a rescaled version of the volume of the area under the graph of
A
A
, in this contribution we show that the other famous concordance measure, Kendall’s
τ
\tau
, allows for a simple geometric interpretation as well – it is inextricably linked to the surface area of
A
A
.