There are many grid templates out there for Photoshop and (i guess, but why?) for Illustrator as well. Grid calculator is an online grid generator that let’s you specify the maximum width of your page, the columns that you need and of course gutter and margin widths. After setting up the values that you need, just click Adobe Illustrator if you want the .ai file or click Adobe Photoshop and you will get a .jsx file. A .jsx file is a script that you can run in Photoshop and in our case it will setup the guides for you.