I have 2 children, one is 1 and the other is 7. Why am I only getting the $3,000 in the tax credit? It's $2,000 per child which would be $4,000.. I don't understand

[CatinaT1]

As far as the Child Tax Credit, this amount can only be used to reduce your tax liability.  If you are not able to use the full credit because your tax liability is 0, you will get the Additional Child Tax Credit. 

These links will provide more information: 

Child Tax Credit 

Additional Child Tax Credit 

[Hal_Al]

The child tax credit  (CTC) is  limited to your tax liability. The CTC is a non-refundable credit and can only reduce your income tax to 0, It can not help you beyond eliminating your tax liability. But, if you have more than $2500 of earned income, some or all of it is usually given back to you thru the "Additional Child tax credit". That is, part of the CTC may be on line 28 of form 1040 (2021 & 2022) instead of line 19. The  ACTC is calculated on form 8812 and  is basically 15% of your earned income over $2500. The ACTC is a maximum of $1500 per child (not $2000).