Tenn. Code § 8-3504
After entering upon participation in benefits established under the retirement system as provided in §§ 8-3501 - 8-3503, a member shall receive during the remainder of his life an annual retirement allowance, payable monthly in equal instalments ceasing with the last instalment due prior to death, in an amount equal to such per cent of his average compensation as shall be determined by the board on the basis of the last actuarial evaluation made as set forth in §§ 8-3427 and 8-3428, multiplied by the total number of years of his current and certified prior service, except that in the case of any member who is a commissioned member of the department of safety, such per cent shall be not less than two per cent (2%). In all cases where any member's compensation has included maintenance or housing the board may fix the value of the same in money and add it to the compensation paid in money when determining such member's average compensation.
No member shall be granted retirement allowance in excess of three-fourths (¾) of his average compensation.
The minimum monthly retirement allowance payable to any class A member or any class B member presently retired, or who shall hereafter retire, shall be four dollars and thirty-four cents ($4.34) for the class A member and five dollars ($5.00) for the class B member, multiplied by the total number of years of his creditable service in either instance.
Any political subdivision which participates in this system may elect, by ordinance or resolution, to provide that the amount of retirement allowance for its firemen and policemen shall be not less than two and one-half per cent (2½%) of their average compensation multiplied by the total number of years of their current and certified prior service. Any political subdivision making such an election shall make a special accrued liability contribution in an amount as determined by an actuarial valuation in the same manner and form as prescribed for initial contributions in § 8-3604.
T.C.A. § 8-3504