I frequently get asked about bio length. The quick answer:
- About.me bios have a 2500 character limit
- Twitter bios have a 160 character limit
- LinkedIn Summary bios have a 2000 character limit
- Speaking bios are typically 75 to 100 words
For checking character or word count, I use charcounter.com
For your own About page (if you have one) or your Branded.me website, length is not as much of a consideration as is good writing. If your bio is interesting to read, then it will be read by the people who matter. Especially for online reading, I like using catchy subheads to break up longer text and to entice a reader to delve into the corresponding paragraph.