I usually get about a tank of fuel or so before the chain needs to be touched-up again. Percentage-wise I’d say about 90% sharp. You could keep cutting with it for a fuzz longer but from my perspective it’s better to bring a few saws with sharp chains and just grab another saw. As a bonus to this method I find the chains last longer when you only need use a few strokes of the file, the files last longer too! .
I agree with this.
My chains last longer with many slight touch-ups, over a few major ones.