Speedometer is not accurate

So these lines of codes should show me the current meters per second of my player, but the actual float just doesnt seem right. What I mean is that, when idle, the value is something random such as: **1.376649e-05** not 0? And when walking the value also changes constantly. The code that im using that every post seems to recommend var vel: Vector3 = rb.velocity; vel.y = 0; mph = vel.magnitude * 2.237;