20 C.F.R. § 404.221
(b) Which of your earnings may be used in computing your average monthly wage.
(c) Number of years to be considered in computing your average monthly wage. To find the number of years to be used in computing your average monthly wage—
(2) If you are a male and you reached age 62 in—
(d) Your average monthly wage. After we find your benefit computation years, we compute your average monthly wage by—
(3) Rounding the quotient to the next lower whole dollar if not already a multiple of $1.
Example:Mr. B reaches age 62 and becomes entitled to old-age insurance benefits in August 1978. He had no social security earnings before 1951 and his year-by-year social security earnings after 1950 are as follows: Year Earnings 1951 $2,700 1952 2,700 1953 3,400 1954 3,100 1955 4,000 1956 4,100 1957 4,000 1958 4,200 1959 4,800 1960 4,800 1961 4,800 1962 4,800 1963 4,800 1964 1,500 1965 0 1966 0 1967 0 1968 3,100 1969 5,200 1970 7,100 1971 7,800 1972 8,600 1973 8,900 1974 9,700 1975 10,100 1976 10,800 1977 11,900 We first find Mr. B's elapsed years, which are the 27 years 1951-1977. We subtract 5 from his 27 elapsed years to find that we must use 22 benefit computation years in computing his average monthly wage. His computation base years are 1951-1977, which are the years after 1950 and prior to the year he became entitled. This means that we will use his 22 computation base years with the highest earnings to compute his average monthly wage. Thus, we exclude the years 1964-1967 and 1951. We total his earnings in his benefit computation years and get $132,700. We then divide that amount by the 264 months in his 22 benefit computation years and find his average monthly wage to be $502.65, which is rounded down to $502.