When you need to autofit all columns of a Kendo grid based on its content, Kendo grid provides an autofitColumn method. Here is an example of how to use this method effectively in following two types of scenarios: 

Two of these issues are addressed in following approach: 

//following function is used to fit all the columns per its content  
kendo.ui.Grid.fn.fitColumns = function(parentColumn) { 
    var grid = this; 
    var columns = grid.columns; 
    if (parentColumn && parentColumn.columns) 
        columns = parentColumn.columns; 
    columns.forEach(function(col) { 
        //recursive call for the grouped columns 
        if (col.columns) 
            return grid.fitColumns(col); 
        grid.autoFitColumn(col); 
    }); 
    //this will expand columns if empty space is left 
    grid.expandToFit(); 
}//fitColumns

//this will expand all the column sizes within kendo grid if  
//there empty space left after autofit
kendo.ui.Grid.fn.expandToFit = function() { 
    var $gridHeaderTable = this.thead.closest('table'); 
    var gridDataWidth = $gridHeaderTable.width(); 
    var gridWrapperWidth = $gridHeaderTable.closest('.k-grid-header-wrap').innerWidth(); 
    // Since this is called after column auto-fit, reducing size 
    // of columns would overflow data. 
    if (gridDataWidth >= gridWrapperWidth) { 
        return; 
    } 
 
    var $headerCols = $gridHeaderTable.find('colgroup > col'); 
    var $tableCols = this.table.find('colgroup > col'); 
 
    var sizeFactor = (gridWrapperWidth / gridDataWidth); 
    $headerCols.add($tableCols).not('.k-group-col').each(function() { 
        var currentWidth = $(this).width(); 
        var newWidth = (currentWidth * sizeFactor); 
        $(this).css({ 
            width: newWidth 
        }); 
    }); 
}//expandToFit

dataBound: function(e) 
{           
    this.fitColumns(); 
}

When the window resizes you can call grid resize as well as fit columns to refit the columns within new width.

$(window).resize(function() { 
    //this assumes that you have grid variables set correctly 
    grid.resize(); 
    grid.fitColumns(); 
});