It seems that the tool accounts only for kernel_x and kernel_y when computing Conv3D MACs:
For W: 8x1x3x3x3, Input: 1x1x32x64x64, Output: 1x8x32x64x64
So if I use only kernel_x and kernel_y (Accounting for a 2D kernel):
MACs = 10.48576 M <---- tool output
If I use kernel_x, kernel_y and kernel_z (Accounting for a 3D kernel):
MACs = 28.31 M <---- calculated as: output_size (in_C // groups (kernel_x kernel_y kernel_z) + bias)
It seems that the tool accounts only for kernel_x and kernel_y when computing Conv3D MACs:
For W: 8x1x3x3x3, Input: 1x1x32x64x64, Output: 1x8x32x64x64
So if I use only kernel_x and kernel_y (Accounting for a 2D kernel): MACs = 10.48576 M <---- tool output
If I use kernel_x, kernel_y and kernel_z (Accounting for a 3D kernel): MACs = 28.31 M <---- calculated as: output_size (in_C // groups (kernel_x kernel_y kernel_z) + bias)