https://taxfoundation.org/2017-tax-brackets https://taxfoundation.org/2017-tax-brackets table 2. To get to $7500 in tax you need to have (7500-1865)/.15 + 1865

https://taxfoundation.org/2017-tax-brackets https://taxfoundation.org/2017-tax-brackets table 2. To get to $7500 in tax you need to have (7500-1865)/.15 + 18650 = ~$56,000 of taxable income. For married filing jointly, standard deduction (same page, table 4) is $12,700. Two personal exemptions (same page, same table) is $8,100. So the total is about $76,800.