Search their website, they used to give vague amounts of how much Techron is in each grade of gas (it used to vary, don't know about now), and they also used to say how much the average tank gets from a bottle.
But like I said it was all vague. So it used to say things like "Texaco fuels are the only gas blends sold with a full dose of Tecron fuel system cleaner. Techron Premium 93 octane includes a full double dose of cleaning power. For maximum cleaning, use Techron fuel system cleaner to get ten times the Techron power." (quotes are an example and should NOT be taken literally, it's an example of the vagueness that used to be on their website, the numbers were made up to use simply as an example).
So like I said it was vague, but it might help you to determine what's a "normal" dose. Do a search for it.
However, simply b/c you don't have a Texaco or Chevron, doesn't mean your gas doesn't have some level of fuel system cleaner in it. I believe (but again don't quote me on this) all fuels sold in the US must have some level of system cleaner (yeah, I really need to double check that, so don't take my word for it). It's just other companies use different additives (Shell uses their "nitrogen" based cleaner, Exxon/Mobil uses something else, etc.)