As reward of your 5-star review, here my lib to compute the size of a text 
Well, this is not really my lib cause I found the trick somewhere in this forum.
Unfortunately I can’t remember who is the real author 
----------------------------------------------------------------------------------------- -- -- textHelper.lua  -- ----------------------------------------------------------------------------------------- local module = {} module.getTextDimension = function(options)   local txt=options.text   options.text=" "   local tempRow = display.newText(options)   local rowHeight = tempRow.height      options.text=txt   local tempText = display.newText(options)   local h=tempText.height   local w=tempText.width   local numRows = math.floor(h/rowHeight)      tempText:removeSelf()   tempRow:removeSelf()   -- return a table with the number of rows & pixel height   return {numRows=numRows, height=h, width = w} end return module
here an example of how you should used :
 local options = { parent = group, text = text, fontSize = fontSizeText, font = self.fontText, align = center, x = screen.width \* 0.20, y = 0, width = screen.width \* 0.60 } local textInfo = textHelper.getTextRowsHeight(options) local tb = display.newText( options ) tb:setFillColor(unpack(self.white)) tb.anchorX = 0 tb.anchorY = 0 tb.y = screen.height / 2 - textInfo.height \* 1.25