This is your highest average salary worked out to a formula designed to give you the best possible calculation – “smoothing out” any adverse ups and downs in your salary over the years, and making adjustments for price inflation.
This is how it works: we determine your salary for each period of 12 months that you have been a USS member, over a maximum time of 13 years previous to the date on which your pensionable salary is to be calculated, and revalue each salary, except the last 12 months, using the Retail Prices Index measure of inflation.
Your pensionable salary is whatever comes out best - either the highest revalued annual salary during the last three years or your highest revalued salary averaged across any three consecutive “best years” over the last 13 years.