If you want to convert word to pdf without changing its format and layout then I would say that you should use a professional online tool like PDFdoctor quickly do the conversion by preserving the original text and layout. If you use this tool then it is assured that the double spacing and font size will be exactly the same in the converted pdf document. The best part is that you can use this tool without downloading any additional tool or app as it browser based converter that can be used on any smartphone in browser or if you like you can also use it on computer or tablet. Just visit and upload your word doc and wait for few seconds to let the magic happen. Your converted pdf file with original text, fonts and spacing would be available in couple of seconds which you can directly download on your smartphone, pc or sync with your cloud storage like Google Drive, Dropbox, etc.
If you are a Microsoft Office user then make sure that you download the free version of Word and see how easy it is to use this Microsoft Office converter. You will love this tool which will make your life a lot easier in the process of converting Word to other formats. For any other software that you use for Word then make sure you try out this tool.