The tentative tax base is the sum of the taxable estate and the "adjusted taxable gifts" (i.e., taxable gifts made after 1976) and the tentative tax is then calculated by applying the following tax rates[19]:* For amounts not greater than $10,000, the tax liability is 18% of the amount.
* For amounts over $10,000 but not over $20,000, the tentative tax is $1,800 plus 20% of the excess over $10,000.
* For amounts over $20,000 but not over $40,000, the tentative tax is $3,800 plus 22% of the excess over $20,000.
* For amounts over $40,000 but not over $60,000, the tentative tax is $8,200 plus 24% of the excess over $40,000.
* For amounts over $60,000 but not over $80,000, the tentative tax is $13,000 plus 26% of the excess over $60,000.
* For amounts over $80,000 but not over $100,000, the tentative tax is $18,200 plus 28% of the excess over $80,000.
* For amounts over $100,000 but not over $150,000, the tentative tax is $23,800 plus 30% of the excess over $100,000.
* For amounts over $150,000 but not over $250,000, the tentative tax is $38,800 plus 32% of the excess over $150,000.
* For amounts over $250,000 but not over $500,000, the tentative tax is $70,800 plus 34% of the excess over $250,000.
* For amounts over $500,000 but not over $750,000, the tentative tax is $155,800 plus 37% of the excess over $500,000.
* For amounts over $750,000 but not over $1,000,000, the tentative tax is $248,300 plus 39% of the excess over $750,000.
* For amounts over $1,000,000 but not over $1,250,000, the tentative tax is $345,800 plus 41% of the excess over $1,000,000.
* For amounts over $1,250,000 but not over $1,500,000, the tentative tax is $448,300 plus 43% of the excess over $1,250,000.
* For amounts over $1,500,000, the tentative tax is $555,800 plus 45% of the excess over $1,500,000.