The special allowance for rental real estate activities with active participation is calculated in Part II of Form 8582. This allowance is a deduction that is available to taxpayers who materially participate in rental real estate activities. The allowance is equal to 25% of the rental real estate income, subject to certain limitations. The calculation of the special allowance is complex and depends on the taxpayer's specific circumstances, so it is important to consult the instructions for Form 8582 for detailed information.