Ohio Rev. Code § 3121.52: Calculating monthly amount due where payments made on other basis.

A court or child support enforcement agency that issues or modifies a support order with support payments to be made other than on a monthly basis shall calculate a monthly amount due under the order, for purposes of its monthly administration, in the following manner:

(A) If the support order is to be paid weekly, multiply the weekly amount of support due under the order by fifty-two and divide the resulting annual amount by twelve;

(B) If the support order is to be paid biweekly, multiply the biweekly amount of support due under the order by twenty-six and divide the resulting annual amount by twelve;

(C) If the support order is to be paid periodically but is not to be paid weekly, biweekly, or monthly, multiply the periodic amount of support due by an appropriate number to obtain the annual amount of support due under the order and divide the annual amount of support due by twelve.