This is a tool to help you calculate fluid grids very easily.
You can choose the number of columns you want, the gap between columns in percents and pressing a button you can see the styles you're going to need and a preview of your grid.
Go to this page to use it https://jeremenichelli.github.io/gridbuilder.
If you feel that something is not working good, or could work better, or if there's something you feel it could improve this tool race the issue here. Thanks!