We study the number of elements and of a finite group such that in the nonabelian tensor square of . This number, divided by , is called the tensor degree of and has connections with the exterior degree, introduced a few years ago in [P. Niroomand and R. Rezaei, On the exterior degree of finite groups, Comm. Algebra ]. The analysis of upper and lower bounds of the tensor degree allows us to find interesting structural restrictions for the whole group.