# Convert bauds to bytes per second

## Online converter

Convert any serial communication speed from / to bauds [Bd] to bytes per second [B/s]. Fill one of the following fields, values will be converted and updated automatically. For more details, check the details explained here.

Speed
Bd
Data bits
bits
Parity
Stop bits
bits

Gross
bytes/s
Usefull
bytes/s

## Explanation

In serial frame, one baud is equal to 1 bit/s. Since one byte is composed of 8 bits, we can deduce the transmission speed in bytes per second by divising by 8:

$$BR_{gross} = \dfrac{BR_{bauds}}{8} \label{eq:daudsgross}$$

with:

• $$BR_{bauds}$$ is the raw transmission speed expressed in bauds
• $$BR_{gross}$$ is the raw transmission speed expressed in bytes per second

A serial frame is composed of the following elements :

• 1 start bit
• n bits of data
• p optional bit of parity (p = 0 or 1)
• s stop bits

Check this page for more details on how a serial frame is built.

But since a serial frame sends start / parity / stop bits, it decreases the usefull rate of transmission. To get the usefull rate of transmission, we need to calculate the ratio between raw bit rate and net bitrate.

• raw bitrate is the total number of physically transferred bits
• net bitrate is the usefull bitrate excluding the physical layer protocol (start, stop and parity bits)

To send n bits of data (usefull bits), we need to send 1 + n + p + s bits. The usefull bitrate is then:

$$BR_{usefull} = \dfrac{n}{1+n+p+s} \times BR_{gross}$$

By replacing $$BR_{gross}$$ by the previous equation \eqref{eq:daudsgross}, we get the final formula:

$$BR_{usefull} = \dfrac{n}{1+n+p+s}\times \dfrac{BR_{bauds}}{8}$$

and vice-versa:

$$BR_{bauds} = \dfrac{1+n+p+s}{n} \times 8 \times BR_{usefull}$$

Where:

• $$BR_{bauds}$$ is the raw speed in bauds
• $$BR_{usefull}$$ is the net speed in bytes per second
• $$n$$ is number of data bits
• $$p$$ is number of parity bits (p = 0 or 1)
• $$s$$ is number of stop bits