Child Tax Credit Calculator
Estimate your Child Tax Credit including income-based phase-outs and the refundable Additional Child Tax Credit.
What This Child Tax Credit Calculator Does
The Child Tax Credit (CTC) is one of the largest tax benefits available to families, potentially worth thousands of dollars per qualifying child. This calculator estimates your total credit based on your Adjusted Gross Income, filing status, number of qualifying children under 17, and any other dependents, correctly applying the income-based phase-out that reduces the credit for higher earners and separating the nonrefundable portion (which can only reduce tax you actually owe) from the refundable Additional Child Tax Credit (which can be paid to you even if it exceeds your tax liability).
This tool is useful for estimating your refund or tax bill before filing, understanding how an income change (like a raise or bonus) might affect your credit if you're near the phase-out threshold, or simply verifying that your tax software calculated your credit correctly.
How It Works
The calculator starts with the maximum possible credit: $2,200 for each qualifying child under age 17, plus $500 for each other dependent (like a child 17 or older, or another qualifying relative) using the Credit for Other Dependents. It then applies the income-based phase-out: for every $1,000 (or fraction thereof) your AGI exceeds the threshold ($200,000 for Single/Head of Household, $400,000 for Married Filing Jointly), the total credit is reduced by $50. Finally, the credit is split into a nonrefundable portion (which offsets your tax liability dollar-for-dollar, but can't reduce your tax below zero) and a refundable Additional Child Tax Credit portion (capped at $1,700 per qualifying child), which can be paid out even if you owe no tax at all.
Formula & Methodology
Maximum Credit = (Qualifying Children × $2,200) + (Other Dependents × $500)
Phase-Out Reduction = ROUNDUP[(AGI − Threshold) ÷ $1,000] × $50
Credit After Phase-Out = Maximum Credit − Phase-Out Reduction
Nonrefundable Portion = MIN(Credit After Phase-Out, Tax Liability Before Credits)
Refundable ACTC = MIN(Remaining Credit, Qualifying Children × $1,700)
Phase-out thresholds: $200,000 AGI for Single, Head of Household, and Married Filing Separately; $400,000 AGI for Married Filing Jointly. The credit phases out completely once the reduction equals or exceeds the maximum credit amount.
Tips & Best Practices
- Know exactly which children qualify — a qualifying child must be under 17 at year-end, related to you, live with you for more than half the year, not provide more than half of their own support, and have a valid Social Security number.
- Watch the phase-out if you're near the threshold — a bonus or raise that pushes your AGI above $200,000 (or $400,000 MFJ) will start reducing your credit by $50 for every $1,000 over, which can meaningfully affect your take-home benefit from a raise.
- Understand the refundable vs. nonrefundable split — if your tax liability is low or zero, the refundable Additional Child Tax Credit ensures you still receive a substantial benefit rather than losing the credit entirely.
- Consider pre-tax retirement contributions to lower AGI — if you're just above the phase-out threshold, increasing 401(k) or traditional IRA contributions can lower your AGI enough to preserve more of your credit.
- Keep documentation for each qualifying child — Social Security numbers, proof of residency, and relationship documentation should be readily available in case the IRS requests verification.
Qualifying Child Requirements in Detail
The IRS applies several specific tests to determine whether a child qualifies for the Child Tax Credit. The age test requires the child to be under 17 at the end of the tax year — turning 17 even one day before December 31 disqualifies them for that year, though they may still qualify for the smaller $500 Credit for Other Dependents. The relationship test requires the child to be your son, daughter, stepchild, foster child, sibling, or a descendant of any of these (like a grandchild or niece/nephew). The residency test requires the child to have lived with you for more than half the year, with exceptions for temporary absences like school, illness, or military service. Finally, the support test requires that the child did not provide more than half of their own financial support during the year, and the child must have a Social Security number valid for employment issued before the tax return's due date.
How the Credit Interacts With Other Family Tax Benefits
The Child Tax Credit is just one of several family-related tax benefits, and it's worth understanding how they interact. The Child and Dependent Care Credit is separate and applies to care expenses that allow you to work, not simply having a qualifying child. The Earned Income Tax Credit (EITC) is also separate, based primarily on earned income level rather than dependent count directly, though having qualifying children significantly increases the maximum EITC amount. Filing status itself matters too — Head of Household status, available to unmarried taxpayers supporting a qualifying child, provides more favorable tax brackets and a higher standard deduction than filing Single, independent of the Child Tax Credit calculation itself.
Common Mistakes
- Claiming a child who doesn't meet the residency test. The child generally must live with you for more than half the year — special rules apply for divorced or separated parents regarding which parent can claim the credit.
- Confusing the Child Tax Credit with the Child and Dependent Care Credit. These are different credits: the CTC is based on having a qualifying child, while the Dependent Care Credit is based on paying for childcare so you can work.
- Forgetting the credit isn't fully refundable. Only up to $1,700 per child of the credit is refundable through the Additional Child Tax Credit; the rest can only offset actual tax owed.
- Not accounting for the phase-out when estimating a raise's impact. Families near the $200,000/$400,000 threshold sometimes don't realize that additional income also reduces this credit on top of pushing them into a higher tax bracket.
Frequently Asked Questions
Related Calculators
For your overall federal tax liability including this credit, use the Federal Income Tax Calculator or Income Tax Calculator. Working families should also check the Earned Income Tax Credit Calculator for an additional potential credit. To see whether you'll owe or receive a refund overall, use the Tax Refund Calculator. To adjust your paycheck withholding to reflect these credits throughout the year, visit the W-4 Withholding Calculator.