Child Disability Benefit Calculator
The monthly top-up paid with your Canada child benefit for each child approved for the disability tax credit. Enter your family income and how many children qualify — the calculator also shows the two earlier years the CRA pays automatically on a first approval.
Read this before using the backdated total. Each earlier benefit year is assessed on that year's own adjusted family net income — the 2023 and 2024 returns, not the figure you entered above. This calculator applies your one income to all three years, so the total below is only accurate if your income barely moved.
If your income changed — a parent left work to provide care, a return to work, a separation, a one-off payout — the real backdated amount will differ, sometimes sharply. Lower income in an earlier year means more benefit than shown here, not less. Treat the total as a rough scale, and confirm each year in your CRA My Account.
Your Child Disability Benefit
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How much is the CDB? For July 2026 – June 2027 the maximum is $3,480 a year — $290.00 a month — for each child approved for the DTC. You get the full amount while adjusted family net income stays at or under $82,847. Above that it drops by 3.2% of the excess with one eligible child, or 5.7% with two or more.
The DTC approval is the whole gate
There is no CDB application. If you already get the Canada child benefit and your child is approved for the disability tax credit, the CRA works out the supplement and adds it to your monthly payment automatically.
So the entire question is whether the child is DTC-approved — Form T2201, certified by a medical practitioner and accepted by the CRA. That single approval also opens the door to a Registered Disability Savings Plan and, for the child's own tax return later, the disability amount itself. If you haven't been through that step, start with the Disability Tax Credit calculator, which covers the eligibility criteria and what the credit is worth on its own.
How the reduction works — and where it differs from the CCB
The CDB has a single phase-out: one threshold, one rate. Take your adjusted family net income, subtract $82,847, multiply the excess by your rate, and subtract that from the maximum.
| Children approved for the DTC | Reduction rate | Maximum (all eligible children) |
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The rate has only two steps — one child, or two or more. A family with three approved children uses the same 5.7% as a family with two. This is the detail most estimates get wrong, because the Canada child benefit's own second-tier phase-out looks almost identical but keeps climbing (8% at three children, 9.5% at four or more). Borrowing the CCB's ladder here would overstate the reduction for larger families.
The other thing to watch: "eligible children" means DTC-approved children only. Four children with one approval is a one-child claim at 3.2%, even though the CCB side of your payment counts all four.
It does not come out of your CCB
The two benefits are worked out independently from the same income figure, then added together into one deposit. The CCB runs a two-tier phase-out across all your children; the CDB runs its single-tier phase-out across only the approved ones. Neither reduces the other, so the supplement is genuinely on top.
They also share a payment schedule — the CDB arrives with the CCB, on the same monthly dates. Both re-index every July using the previous year's income, so your amount changes each July even if nothing about your family did. Use the Canada Child Benefit calculator for the base payment.
The two backdated years
On a first CDB approval the CRA automatically calculates the current benefit year and the two previous ones, and pays the difference. Older years are still possible, but you have to send a written request to your tax centre rather than getting it automatically.
That is a much shorter window than the disability tax credit itself, which the CRA can reassess up to 10 years back. The two often arrive together after a T2201 approval — a retroactive DTC reassessment on the parent's returns, and a retroactive CDB top-up on the child benefit — which is why the totals can look surprisingly large.
Each of those years is assessed on its own income, and that is the catch. The benefit year running July 2024 – June 2025 uses your 2023 adjusted family net income; July 2025 – June 2026 uses 2024. A backdated estimate that applies today's income to all three years — including the one above, unless you work each year out separately — will be wrong for any family whose circumstances changed. That is not a rare case: a disability diagnosis in a young child often coincides with a parent reducing hours or leaving work, which pushes income down in exactly the years being backdated. Lower income then means a larger retroactive payment than a flat estimate suggests. The direction of the error is at least in your favour, but the size of it is not something to plan around — check each year in My Account.
CDB means two different programs — check which one you want
Two federal programs share the initials, and they are not related:
- Child Disability Benefit — this page. A monthly, tax-free CCB supplement for a child under 18 approved for the DTC. Income-tested on adjusted family net income.
- Canada Disability Benefit — a separate federal payment for working-age adults with disabilities, with its own application and its own estimator on the government's site.
Both use DTC approval as a gateway, which is the source of most of the confusion. If the person with the disability is an adult, this is not the right calculator.
Common questions
How much is the Child Disability Benefit?
Up to $3,480 a year ($290.00 a month) per approved child for July 2026 – June 2027, full amount while adjusted family net income is $82,847 or less, then reduced by 3.2% (one child) or 5.7% (two or more) of the excess.
Do I need to apply?
No. With the CCB in place and the child DTC-approved, the CRA adds it automatically. The application that matters is Form T2201 for the disability tax credit.
How far back is it paid?
The current benefit year plus the two previous ones, automatically. Earlier years need a written request to your tax centre.
Does it reduce my Canada child benefit?
No. They're calculated separately from the same income and added together in one payment.
Is it taxable?
No. Like the CCB, the CDB is tax-free and doesn't go on your return as income.
At what income does it stop?
With one approved child, at roughly $191,597 of adjusted family net income. With more approved children the maximum is larger and the rate is higher, so the zero point shifts — the calculator shows yours.