How did they come up with the 1040a tax table?

Answer by  Taxmatters (169)

The rates for 1040-EZ, 1040-A and 1040 are the same. The rates are set by congress and the percent due is based on the amount of your income.

Answer by  Christian9247 (5042)

The amounts are the same per each form whether you use 1040-EZ or 1040-A or just the standard 1040. The rates are set by Congress and percent due is based on the amount of your annual income. There is a rhyme and a reason to the chart. Taxes simply don't make sense to begin with!