I would have said that the best age to start planning for retirement is Agee 25, but what if there has not been any source of income. My advice is immediately one secure a job after 25 years, it the best time to start retirement plan.It's all about your stamina and depends about your health conditions.some people with 60 age are very active and energetic but on the hand some people with age 50 didn't feel fit for jobs