What is the difference between bit rate and baud rate?

What is the difference between bit rate and baud rate?

What is the difference between bit rate and baud rate, and when is bit rate equal to baud rate?

    Requires Free Membership to View

    By submitting your registration information to SearchNetworking.com you agree to receive email communications from TechTarget and TechTarget partners. We encourage you to read our Privacy Policy which contains important disclosures about how we collect and use your registration and other information. If you reside outside of the United States, by submitting this registration information you consent to having your personal data transferred to and processed in the United States. Your use of SearchNetworking.com is governed by our Terms of Use. You may contact us at webmaster@TechTarget.com.

Bit rate is a measure of the number of data bits (that's 0's and 1's) transmitted in one second. A figure of 2400 bits per second means 2400 zeros or ones can be transmitted in one second, hence the abbreviation 'bps'.

Baud rate by definition means the number of times a signal in a communications channel changes state. For example, a 2400 baud rate means that the channel can change states up to 2400 times per second. When I say 'change state' I mean that it can change from 0 to 1 up to 2400 times per second. If you think about this, it's pretty much similar to the bit rate, which in the above example was 2400 bps.

Whether you can transmit 2400 zeros or ones in one second (bit rate), or change the state of a digital signal up to 2400 times per second (baud rate), it the same thing.

So we can conclude that in the above example, the bit rate is the same as the baud rate. Hence, 1 bit rate = 1 baud rate for this example.

There are cases though where a channel can send 4 bits per baud, meaning that for every 4 bits, we have one change, and in this case, the baud rate is 1/4th of the bit rate.

This was first published in July 2003