Determine Your Obligation Assessment
For the convenience of our employer customers, below are instructions to help you figure your 2018 obligation assessment.
The 2018 rates are as follows:
 OA ratio = 0.171757
 Base assessment = $63.00
 Taxable wage base=$9,000
The example calculation below is based on a fictional employer with a 2018 tax rate of 10.30% and 1,500 employees.
Instructions:
 Divide your tax rate (10.3) by 100. The result should be 0.103.

Next, multiply 0.103 by the OA Ratio of 0.171757 (0.103 X 0,0.171757). Did you get 0.017690971? Good, that’s correct. Jot this number down.
 Now divide the Base Assessment by the Taxable Wage Base (63/9000). You should get 0.007. Next, add this number to the number you saved above and multiply the result by 100. (0.017690971 + 0.007 X 100). If you get 2.4690971, you’re right. Always round up this number to the next hundredths of a percent. So now you should have 2.47. This is your 2018 OA Rate (2.47%).
 To obtain your cost per employee, multiply this example’s OA Rate of 2.47 by the taxable wage base of $9,000. You should get a cost per employee of $222.30.
 To obtain the total cost for the example employer, enter the cost per employee of $222.30 and multiply it by the number of employees, which is 1,500 in this example. You should get $355,450 as the total cost for the example employer.
Example Results Summary:
 OA Rate = 2.47
 Cost Per Employee = $222.30
 Total Cost For Employer = $333,450
*Since most employers qualified for the $9,000 taxable wage base, this was used in the calculation instead of the higher taxable wage base of $9,500.