$ npm install px_to_rem
Utility for converting font-size css styles using px units to rem
var px_to_rem = require('px_to_rem');
var css = "h1 { \n font-size: 12px;\n }";
var output = px_to_rem.convert(css);
console.log(output);
Also included is a command line tool that takes a css file as an argument (cwd = base folder of plugin)
$ ./px_to_rem style.css