The general principle is that you don't count the stop that you are at. From this, we can derive the following scenario.
You're at station A and want to get to station D. You don't know yet that there are only stations B and C in between. You ask the station attendant/person waiting/someone who knows:
How do I get to D from here?
The attendant replies:
Oh, just get on the train/bus/subway and go 3 stops.
the stops being B, C, and your goal D, and you don't count the stop you're at. Looking at the map, B is 1 stop, C is 2 stops, and D is 3 stops, you count from one starting with the next stop and you stop counting on the goal. "Go 3 stops." -> count to 3, the stop you're on at 3 is your goal.
To be explicit, let's follow this all the way to your destination D.
So you've just got on the bus at A, and someone asks (the bus may have started up or maybe not left yet):
How far to D?
The correct and universally understood response that you make (because now you know) is:
Now you're on the bus and it has stopped at B. Same question How far is D?:
2 more stops til D
(works also if the bus is between B and C)
The bus is at C now. How many more stops?
1 more stop
If you're between C and D, its either
1 more stop.
The next stop is where we get off.
You're coming up on D... what do you say to someone who doesn't know? All they know is that they're still between C and D. The answer is mostly the same.
This is our stop.
It's coming up now.
1 more stop.
The next stop.
So the principle is, don't count the stop you are currently at.
As an aside, 'normal' people count starting from 1. I make this explicit because some technically minded people start counting from 0, which is logically consistent only if you are considering the empty set. So you could say that you can count this stop if you also start counting at 0.