First, get a count of your full time employees by including only employees that have either 130 hours of service for a given month OR 30 hours per week on average per month.
It's important to be consistent in your measurements and use either a monthly or averaged weekly count and not both.
Next, calculate your total full time equivalent employees by adding up the hours of all part time employees for the month, making sure not to include more than 120 hours of service per employee.
Next, take this sum and divide it by 120 to get your full time equivalent count.
Finally, add your full time employee count to your full time equivalent count to determine whether you may need to file ACA forms.
IMPORTANT: Make sure to add together your full time + full time equivalent employee counts for all companies that share common ownership.
Example:
Company A has 30 full time + FTE employees.
Company B has 25 full time + FTE employees.