There's obviously some sort of boundary marker within most Space Faring species / groups.
At what size points do you transition from the categorizations of Shuttle > Runabout > StarShip
Shuttle:
<20m
Atmospheric flight and landing primary design feature
Days of operation
Max 6 people
"Micro" version power plant
Low warp, heavy use of impulse and thrusters
One low cycle transporter if at all
Runabout/Aeroshuttle/Support craft:
<50m
Atmospheric and spatial flight modes equally
Weeks of operation
Max 8-20 people
Support craft level power
Warp, impulse and thrusters equally
Transporter pad
Transport/Hauler/Colony ship:
~100m
Either deep space linear travel or inter-planetary landing and takeoff
Months of operation
Max 50-150 people
Mass production power assembly
Warp and impulse main
Transporter rooms
Starship:
Open ended size starting at 100m
Next to no planetary based flight except when needed
Years of operation
Crew 200+
Heavy output power reactor
High warp and multiple impulse assemblies
Transporter rooms and mass bulk cargo transports