To calculate the total number of eigenvalues smaller than a specified value in MATLAB, one can use the following approach: first, compute the eigenvalues of the matrix A using the command E = eig(A). Then, identify the eigenvalues that are smaller than the specified threshold c by using the command F = find(abs(E) < c). Finally, the count of these eigenvalues can be obtained with size(F). This method applies to both real and complex eigenvalues, depending on the matrix A used in the calculation.