Is Multiplying the Inverse Better or Worse?

Question

When dealing with double data types is multiplying by the inverse better or worse?

Which way is faster? Which way uses

Answer 1

The benefit will be very small or zero, depending on both the compiler and the hardware.

But it could still matter (in a tight loop), and then for readability you should write

SquareInches = MMSquared * (1 / 645.16)

And preferably use a constant for 645.16.