Budgeting for Vacation & Sick Replacements

brark

I am looking for a formula or method to budget for vacation and sick leave replacements. I thought at a prior employer we used one where you plugged in the amount of vacation and sick accrued and then did a mathematical calculation or percentage. That way you could build into the budget money for replacements for hourly staff. Does that sound familiar to anyone or do you have something you use? Your help and ideas would be greatly appreciated.