DPI vs Image size for webposting

I was talking with a photog friend of mine today and she suggested that I really fix my website pics. She said that the pics are pulling up very grainy and sometimes with heads cut off. She suggested that I post everything at 72 dpi. When I checked this the photo that I had posted was at 72 dpi. Does the dpi and the image size have to be adjusted and if so what is a good size to post?

I don't see any of this when I pull up the site on my screen but could that be because I am using a 22" screen?

I dont think DPI will be the cause of this, more like picture size in pixels. For the web i usually save my photos at 800 pixels on the longest size, many sites have constraints, im no expert so hope others more experienced can enlighten you further.

DPI is meaningless as far as web sites and viewing on monitors are concerned.

When uploading your images to your web site, size them using pixel count. Also experiment with the jpeg compression as this will effect the graininess of the image.

DPI is used to calculate how many pixels are required to PRINT to a certain size. An example would be if you wanted to print a 10" x 8" photo and your printer were to require 300 dpi then you would need to make the image 3000 pixels by 2400 pixels.

Steve

Agree with the guys above, keep your images to a reasonable pixel size, and then display them full size (rather than use HTML to make the smaller/bigger)

Thanks you guys. Very informative. I did contact my webhost today and it's because I have a FULL screen site. So changing my pics wouldn't matter any way. I'm glad that I didn't go through all the work changing them first! So, the solution...to pay for a template change.