You may have heard about the Australian Walking Track Grading System. It filters tracks by the level of fitness, experience and equipment required for each walk and grades them from 1 to 5. A grade 1 walk includes easy, accessible walks suitable for everyone, while grade 5 tracks are reserved for experienced and well-prepared walkers only. Caro from Lotsafreshair explains the AWT Grading System in more detail here.
Whilst it may be in-precise at times, its the closest we have here in Australia to a standard for all walks.