To calculate your plan compensation, you reduce your net earnings from self-employment by: the deductible portion of your SE tax from your Form 1040 return, Schedule 1, on the line for deductible part of self-employment tax, and the amount of your own (not your employees’) retirement plan contribution from your Form 1040 return, Schedule 1, on the line for self-employed SEP, SIMPLE, and qualified plans. You use your plan compensation to calculate the amount of your own contribution/deduction. Note that your plan compensation and the amount of your own plan contribution/deduction depend on each other - to compute one, you need the other (this is a circular calculation). One way to do this is to use a reduced plan contribution rate. You can use the Table and Worksheets for the Self-Employed (Publication 560) to find the reduced plan contribution rate to calculate the plan contribution and deduction for yourself.
