Chart of Roth conversion example
0 With a Roth conversion
1 Original estate value $21 million
2 Amount converted to Roth $8 million
3 Conversion taxes due (37%) $8 million x 37% = $2.96 million 
4 Reduced estate $21 million – $2.96 million = $18.04 million 
5 Estate tax exemption $12.92 million
6 Taxable estate $18.04 million – $12.92 million =$5.12 million 
7 Estate taxes due (40%)1 $5.12 million x 40% = $2,048,000