Deferred Tax Asset/Liability with an NOL

I am calculating DTA and need to know what effective tax rate to use. Background: LLC converted a C Corp effective 5/30/2014 Company is a start-up with no revenue - only development costs. At the end of an initial audit by Deloitte in preparation of a possible equity event. At the date of the conversion I need to calculate the Deferred tax assets & liabilities. I have identified the timing differences and I have calculated the loss that can not be used by the members of the LLC at the date of conversion. Question: With no revenue stream now or in the foreseeable future the company is only generating net losses. What effective tax rate do I use to multiply the timing differences and loss to date to create the Deferred Tax Asset?