Key Takeaways For people between the ages of 25 and 34, the average retirement account balance is $42,640 and the median is $16,255. For those between the ages of 35 and 44, the average balance is $103,552, and the median is $39,958. A 30-year-old millennial with the median amount saved for retirement ($16,255) could grow their nest egg to $1.2 million by age 65 if they contribute about $636 per month for 35 years. A 40-year-old millennial with the median amount saved for retirement ($39,958) could ...