An asynchronous receiver/transmitter provides autobauding with adjustment to a programmable baud rate. A baud divisor is calculated based on a detected size of a start bit. The asynchronous receiver/transmitter provides a plurality of baud divisor replacement registers, each register storing a baud divisor threshold and a baud divisor replacement. The baud divisor is compared to the plurality of programmed baud divisor thresholds. Based on the performed hardware comparison, the baud divisor is automatically replaced by a baud divisor replacement for a particular baud divisor range defined by a baud divisor threshold and including the baud divisor. The baud rate corresponding to this baud divisor replacement represents the appropriate baud rate. Autobauding with adjustment to a programmed baud rate corrects for measurement inaccuracies with respect to the start bit size. Autobauding with adjustment to a programmed baud rate also permits an asynchronous receiver/transmitter to reliably support high speed baud rates. Further, the programmable nature of the baud divisor thresholds and baud divisor replacements permits an asynchronous receiver/transmitter to support autubauding at multiple asynchronous receiver/transmitter frequencies.