Are you talking about DTA/DTL? Basically you just need to calculate the carrying value and the tax base seperately. Compare those 2 numbers, take the difference and times it by the tax rate. If Tax Base > Carrying value = DTA. Tax Base < Carrying Value = DTL. Basically, you will be paying the same amount in taxes, its just a matter of when you pay them. DTA/DTL smooth the tax expense as opposed to having a huge tax hit now or in the future.