Choose a filing status first, then test each dependent and each credit separately. Filing status, dependent status, the Child Tax Credit (CTC) and Additional Child Tax Credit (ACTC), and the Earned Income Tax Credit (EITC) use different definitions. A person can count as your dependent and still not produce a CTC, an ACTC, or an EITC.
The calculators linked below estimate each piece from the facts you enter. They do not prepare or file a return, make any election, or confirm eligibility from records they cannot see. Treat each output as a comparison to check against current IRS instructions.
What is the difference between comparing and being eligible?
A comparison asks which result is lower or higher if you assume a set of facts. Eligibility asks whether the law lets you use a status or claim a person on your return. The Filing Status Comparison Calculator can show single and married filing jointly side by side. It cannot tell you that you qualify for head of household, or that you are treated as unmarried.
Marital status on the last day of the year, who lived in your home and for how long, and who paid the household costs decide which statuses are open to you. Publication 501 is the IRS source for filing status, dependents, and the standard deduction. If a comparison shows one status is lower, confirm that you can legally use it before relying on that figure. For the status checks themselves, see Single, married filing jointly, or head of household: what must be checked?
Why are dependents, CTC, ACTC, and EITC separate?
Each is a different rule system, with its own tests and its own place on the return.
| Item | What it answers | Where to check |
|---|---|---|
| Dependent | Can you claim this person on your return? | IRS dependents page, Publication 501 |
| CTC | Does a qualifying child under 17 reduce your tax? | IRS Child Tax Credit page, Schedule 8812 |
| ACTC | Does any unused CTC come back as a refund? | Schedule 8812 instructions |
| EITC | Do your earned income, AGI, filing status, and qualifying children produce this credit? | IRS EITC page, Publication 596 |
The tests overlap but do not match. The IRS lists five tests for a dependent qualifying child: relationship, age, residency, support, and joint return. The age test is under 19, or under 24 for a full-time student, or any age if permanently and totally disabled. The residency test is more than half the year. The child must also not have provided more than half of their own support Publication 501.
The CTC is narrower. For the 2025 tax year, the child must be under 17 at the end of the year, be claimed as your dependent, and be a U.S. citizen, U.S. national, or U.S. resident alien. You (and your spouse, if filing jointly) and the child must each have a Social Security number valid for employment, issued before the return's due date, including extensions IRS Child Tax Credit.
A 17-year-old who passes the dependent tests therefore gives no CTC. Schedule 8812 puts that child on the "other dependents" line instead, with the credit for other dependents (ODC) Schedule 8812, 2025. The same applies to a child under 17 who lacks the required SSN.
How does adding a dependent change a tax estimate?
The change depends on which credits the dependent opens, so count the dependent and the credit-eligible child separately. Filing status can also change, for example to head of household. A dependent can affect the CTC or ODC, the EITC, and filing status. Each of those has its own inputs. The Dependent Tax Impact Calculator is for the first estimate; the explanation is in How does adding a dependent change a tax estimate?
The tie-breaker rule applies when a child is a qualifying child of more than one person. A parent generally takes priority over a non-parent. If both parents claim the child and do not file jointly, the child goes to the parent with whom the child lived longer. If the time is equal, it goes to the parent with the higher AGI IRS tie-breaker rule. A calculator that counts one child on two households' estimates has not applied this rule.
What do CTC and ACTC mean in dollars?
The CTC is nonrefundable. It reduces tax liability but, by itself, does not produce a refund. The ACTC is the refundable portion IRS Child Tax Credit.
For the 2025 tax year, the IRS states these amounts:
- CTC: up to $2,200 per qualifying child.
- ACTC: up to $1,700 per qualifying child, depending on income.
- Earned income of at least $2,500 is required for the ACTC.
The IRS CTC page gives the $2,200 and $1,700 limits and the $2,500 earned-income requirement. H&R Block's description of the formula, 15% of earned income above $2,500, matches the commonly stated ACTC rule. Confirm it on the ACTC lines of Schedule 8812 and its before relying on it.
The CTC phases out at higher income, and the dollar thresholds and rate depend on the tax year and filing status. I did not verify these for this page. Look them up in the Schedule 8812 instructions for the year you are filing. For the 2026 tax year, the IRS draft instructions show the same $2,200 CTC and $1,700 ACTC limits, but a draft can change 2026 draft instructions.
Example: the earned-income limit on the ACTC (assumed facts, 2025 tax year)
Assume one qualifying child under 17 with a valid SSN, and no ACTC limit other than the earned-income formula and the per-child maximum. This is only the earned-income limit, not a full return.
- Earned income of $20,000: 15% × ($20,000 − $2,500) = $2,625. The per-child maximum is $1,700, so this limit is $1,700.
- Earned income of $3,000: 15% × ($3,000 − $2,500) = $75.
The ACTC is also capped by how much CTC is unused after your tax is figured, and the phase-out can reduce the credit. The example shows only that earned income, not household size, limits the refundable amount at low incomes. It does not predict a refund. The Child Tax Credit and ACTC Calculator estimates these amounts; for the difference between the two credits, read Child Tax Credit vs. Additional Child Tax Credit.
How does the EITC differ from the CTC?
The EITC has its own definition of a qualifying child and its own income tests. Earned income, AGI, investment income limits, filing status, and the number of qualifying children all enter the calculation. Don't reuse CTC eligibility as EITC eligibility, or the reverse. Filing status can change EITC eligibility, so run the status comparison and the credit check with the same assumptions. The credit amounts, phase-in and phase-out ranges, and investment income limit change each year, so take them from the EITC page and Publication 596 for your tax year.
The Earned Income Tax Credit Calculator gives an estimate from the numbers you enter. The deeper rules are in EITC eligibility: income, children, and filing status.
What records do you need before using the calculators?
Gather these first. Missing or wrong inputs are the most common reason a calculator result differs from the return.
- Marital status on December 31 and each person's date of birth.
- The number of months each child lived in your home, and who provided the support.
- Each person's Social Security number type and issue date.
- Wages, self-employment net earnings, and other earned income, kept separate from AGI.
- Whether another person could also claim the same child.
- The tax year you are estimating, so every threshold comes from one year's instructions.
Use the estimate to compare scenarios. A withholding or payroll figure is not the same as final tax on the return, and state rules are separate from the federal ones. Check your state tax agency's page for state filing status and dependent rules.