What is indicated altitude when the altimeter reads 12,600?

Indicated altitude is the altitude read directly from the altimeter, assuming it has been properly calibrated to the local barometric pressure setting. When the altimeter reads 12,600 feet, that number reflects the altitude at which the aircraft's pressure level coincides with 12,600 feet of standard atmospheric pressure.

This value does not account for variations in atmospheric pressure or errors in altimeter calibration; it simply reports what the instrument shows. Therefore, the correct understanding is that the indicated altitude corresponds directly to the reading on the altimeter, which in this case is 12,600 feet. Altimeter settings are crucial, but the number displayed indicates the altitude above sea level based on the current setting, making the selected answer accurate.