For most taxpayers, the credit for other dependents is a flat $500 per qualifying dependent, so you can simply multiply $500 by the number of qualifying other dependents you have, and subtract the total from your tax obligation. The credit cannot reduce your tax obligation below zero. If you make more than $200,000 (single) or $400,000 (married filing jointly), your tax credit will phase out roughly $50 for every $1,000 you make over the cutoff. The easiest way to make sure you calculate it correctly is to use the IRS calculator.