I know I am a bit late for answering, but this is how friction is calculated for ground movement in UE4 character movement component
Velocity = Velocity - ((Velocity * Friction) + Braking Deceleration) * Delta Time
Friction is only used in case of braking its not added when accelerating
Friction = Ground Friction * Braking Friction Factor
if you still searching for calculating stop location I posted my code here: Predict Stop Position of Character ahead in time - Character & Animation - Unreal Engine Forums