# PIC UART baud rate calculator

Another quick post. I needed to calculate the UART baud rate generator register
value for different rates and the error I was having because the internal clock
I was using, 32 MHz, does not neatly divide into any of the more standard values
so I fired up a LibreOffice spreadsheet and made it show me what configuration
matches the desired baud rate the best, the error, and it also neatly paints
the error values in red / yellow / green colours depending on whether the error
percent is above 1%, below 1%, or **exactly** 0% so for my 32 MHz clock it
shows:

*Download the LibreOffice Calc document here.*

Only some not really standard but widely supported baud rates like 250000 and 500000 bps match exactly, although many standard rates have error margins well below 1% but if I had chosen a proper UART clock like 12.9024 MHz the table would look greener:

And also some “can’t do” baud rates where the “correct” register value would be negative 😉