Simple online grid image generator.
GridCalc is a easy to use grid calculator. Just enter the desired width of your page and an aproximate range for your column and gutter width and the calculator will give you all the possible combinations within the limits you entered. You get a nice visual representation of the results, click preview on a result and you get a better presentation of how the grid can be used. When you have decided which grid configuration you want to use you can download the configuration as a css file to use in your project.