Scaling for your drawings:
- a small stand is 5 x 5 large square and with the road piece they're 5 x 7.
- a large stand is 10 x 8 large squares, and with the road piece, they're 10 x 10
Each large square is made up of 4 x 4 small squares. Small squares are the width of walls, bathroom stalls, single doors, etc. So a large stand is 40 small title - if each is considered a 1m metre square, then a large stand is 40 m wide. This is about right as the wing span of a 737 is 37 metres.
So this means for gates for a 747 - we would need a stand that is 65 metres wide and 80 metres long, so 18 x 20 large tiles, plus 2 for the road, giving 18 x 22 (likely 20 x 22 as it's makes it easier for building). An A380 would need 85 metres by 80 metres long - so 22 large tiles by 22 large tiles. So I could see a large stand being made at 22 x 22 large tiles to handle all widebody jets.
Taxiway is 5 large tiles wide and the small runway look about the same width.
Road lanes are 1 large tile wide, two lane roads are 2 large tiles wide