The tax computation using maximum capital gains rates refers to the calculation of the taxpayer's tax liability on capital gains using the highest tax rates that apply. The maximum capital gains rates are 20% for individuals in the highest tax bracket and 23.8% for net investment income. The taxpayer must determine their taxable income, calculate their capital gains, and apply the maximum capital gains tax rate to determine their tax liability. This calculation is important for understanding the potential tax impact of realizing capital gains and can help the taxpayer plan their tax strategy accordingly.