I have self-employment income and have set up a SIMPLE IRAin which I plan to direct both my "employee" contribution of up to $6000, and my 3% "employer" contribution. I understand that as an "employee" the amount that is available for my contribution would be after my 7.65% "employee" FICA amount is deducted.
My question is whether I need to also to deduct my "employer's" 7.65% FICA amount before I determine what amount is available to contribute.

I believe you do. According to IRS Pub 590, "For purposes of the plan rules, if you are self-employed, your compensation for a year is your net earnings from self-employment (line 4, Section A of Schedule SE (Form 1040)) before subtracting any contributions made to a SIMPLE IRA on your behalf."

Hope this helps.

I am assuming you have no employees and have elected a 3% matching contribution.

The formula for a Self-Employed SIMPLE IRA Contribution is as follows:

First, determine the self-employed's Compensation:

Net Earnings from Sch C X .9235=Compensation

Next determine the deferral amount:
Max Deferral= 100% of Compensation or $6000, whichever is less

Last, determine the employer matching contribution:
3% Match= 100% of Deferral, up to $6000, or 3% of Compensation, whichever is less

For example:

Net Business Profits (Sch C) =$50,000

Compensation= $50,000 X .9235 =$ 46,175

Max Deferral= $6,000

Matching Cont.= $46,175 X .03 =$1,385.25

Total Cont.= $6,000 + $1,385.25 =$7385.25

You are correct, but do understand that the term self-employment income is determined after the employee's wages, FICA, and other expenses are deducted) to arrve at "botton line" EI. After that, in determining NESE under the SIMPLE plan, only .9235 percent is used according to the IRS.