Many conditions within systems in my game are based on velocity of the character to calculate certain things. Many use the full vector (x, y, z), while others I need to convert x and y into a 1 dimensional scalar (float) to get the overall speed.

I tried using Character Movement and breaking its velocity vector into 3 floats, and then converting the x and y to ABS (absolute float) and then adding x and y together. When I do this, depending on the direction Im facing the float can be as high as 800 when other times its quite low. In theory if I add them together properly, the 1d float should never change as long as the Max Walk Speed driving the character never changes.

So my question is, what formula or process would I need to do to convert a 2d vector into a 1 scalar as a float that represents current speed/acceleration?