1)PUt your table "as is" so the first value (the zero) is in Cell A3
2)Put any taxable amount in cell H1
3)Put this forumula in cell I1:
=VLOOKUP(H1,$A$3:$E$8,3,1)+(H1-VLOOKUP(H1,$A$3:$E$8,5,1))*VLOOKUP(H1,$A$3:$E$8,4, 1)

Does that help?

Regards,
Ron