Mo. Rev. Stat. § 442.530

When a party as tenant for life, or by the curtesy, or in dower, is entitled to the annual interest on a sum of money, or is entitled to the use of any estate, or part thereof, and is willing to accept a gross sum in lieu thereof, or the party liable for such interest, or affected by such claim, has the right to pay a gross sum in lieu thereof, or if the court in any legal proceedings adjudge or decree a gross sum to be paid in lieu thereof, the sum shall be estimated according to the then value of an annuity of six percent on the principal sum during the probable life of such person, according to the following table, showing the present value, on the basis of six percent interest, of an annuity of one dollar, according to the Carlisle tables of mortality, payable at the end of every year that a person of a given age may be living for the ages therein stated: