Liz Weston: How does Social Security calculate estimates of future benefit amount?

Dear Liz: A while back, you responded to a letter writer that Social Security’s estimates of the amount a person will receive assumes the person will continue working until they apply for benefits. I thought the amount a person receives was based on the average of the highest 30 years’ of earnings over a person’s entire career. Can you please clarify?

Answer: Social Security retirement benefits are based on your 35 highest-earning years. To estimate your future benefit, the agency assumes you will continue working for a similar wage to the one you’re making now, and that you will do so until you apply. The agency compares these projected earnings years with those you’ve already had, and picks the top 35 years to determine your estimate.