Is a child tax credit standard or calculated?

The 2014 child tax credit is a standard $1,000 credit per child, although there are some limitations. The credit starts to phase out when married couples filing jointly have a modified adjusted gross income of more than $110,000, according H&R Block.

For single taxpayers, the credit starts to phase out when their income is more than $75,000. In all cases, the credit is limited to the amount of tax an individual owes, notes the Internal Revenue Service. Taxpayers can claim the credit for any child they claim as a dependent, including grandchildren, nieces and nephews. The credit applies to children who are age 16 or younger when the tax year ends.