CASBO has developed a formula to serve as a helpful starting point for determining custodial staffing. The formula provides a convenient, quick ballpark staffing figure. However, other factors should be taken into consideration, which could affect your staffing figure, such as an extremely large school campus or a campus that holds constant events and needs multiple cleanings a day.

The formula:

  • One custodian for every 325 students
  • One custodian for every 13 teachers
  • One custodian for every 13 classroom units
  • One custodian for every 18,000 square feet of educational space
    • Use the average of these four factors to determine your full-time equivalent (FTE)
  • Add .3 FTE for a school site with less than 450 enrolled students
  • Add a community use factor
    • Elementary: .0625 FTE
    • Middle: .25 FTE
    • High School: .5 FTE

CBOs in need of a more precise staffing figure should utilize the International Sanitary Supply Association (ISSA) formula. While the ISSA formula is very accurate, it is also labor intensive and time consuming. Both formulas will be covered in the CASBO School Business University (SBU) online course, Maintenance & Operations for the New Director, launching in February. Learn more in CASBO SBU!