servo goes to 100 when I say 80

so, I bought a plastic robot kit, and some servos.

I’m sending servo angles to the leg, but the servos are mounted so that the tibia servo is backward from the other servos. incidentally, 30 degrees is in the right place for the other servos, but sending 30 degrees to the tibia servo assigns the servo to my robots 150.

I’ve searched for servo posts related, but where people seem to be asking how to do what I want to do, there aren’t clear answers, so I didn’t manage to answer my question.

can you just map 0-180 to 180-0??

Don't bother with map() - though that'd work.

Just subtract the angle you want from 180 and set it to that angle...

It would be quicker to just try it than to ask on this forum. map(...) will work but the resolution may or may not be acceptable. The solution presented by DrAzzy is even better, especially since you can use float (or double) if you need better resolution.