This disability tax credit calculator gives you a rough dollar figure for what the DTC could be worth to you, for the current tax year or across retroactive claims. It is a planning tool rather than an official figure, so do not build financial decisions on it, and it does not decide whether you are eligible. Only approval of Form T2201, the disability tax credit certificate, confirms that.
Canadian Benefits Association is a private company and is not affiliated with any government agency. You can do the Disability Tax Credit paperwork yourself, free of charge.
How the disability tax credit is calculated
The DTC is a non-refundable tax credit, so it reduces tax payable rather than producing monthly payments. The calculator takes the federal disability amount for each tax year and multiplies it by the lowest federal tax rate, then adds the provincial credit, since most provinces set their own disability amount and their own rate. That is the whole of it: two credits, calculated separately, claimed on the same return.
The federal disability amount
For 2026 the federal disability amount is $10,341 and the federal rate is 14 percent, which makes the federal credit worth about $1,448 for an adult. For 2025 the base was $10,138 at 14.5 percent, or about $1,470. The base is indexed to inflation every year, so the disability tax credit amount is different in every year you claim, and a calculator that uses one figure for all ten years will be wrong.
The provincial portion
Most provinces add their own disability amount on top. The provincial portion uses that province’s base and that province’s lowest rate, so federal and provincial amounts have to be worked out separately and then added. Two people with identical approvals in different provinces end up with different totals, which is why the province field changes the answer.
An Ontario example
Ontario is the clearest illustration. The provincial tax rate in Ontario is 5.05 percent, applied to Ontario’s own disability amount for that year, and the result is added to the federal disability tax credit for the same year. Run the same claim in a province with a higher lowest rate and the provincial side comes out larger, even though the federal side has not moved.
The child supplement and the usable amount
Where the person with the impairment was under 18 at the end of the year, an additional supplement applies on top of the base: up to $6,032 for 2026. That supplemental amount is what makes a child disability tax credit calculator produce a larger figure than an adult one for the same year.
When the supplement is reduced
The supplement is reduced by child care or attendant care expenses claimed for that child by anyone, above a threshold. Families paying for significant care often receive less than the maximum, and in some years the supplement is reduced to nothing while the base amount still applies.
Why the tax payable cap matters
Then the cap. Because this is a non refundable credit, the usable amount can never exceed the tax otherwise payable in that year. A year with no taxable income produces no usable credit, no matter how severe the impairment. This single rule is the reason most estimates people are given are too high.
What to have ready
Your province or territory, since provincial amounts differ.
The retroactive years you want included, up to the ten years that can generally be reassessed.
Income tax paid in each of those years, from your notices of assessment.
Whether the claimant was under 18 or an adult in each year.
Whether the credit would be claimed by a family member.
What the calculator assumes
It assumes approval for every year you include, indexed federal and provincial amounts for those years, the lowest marginal rates, and that the income received in each year is enough to use the credit where you have said it is. Change any of those and the number changes. Enter actual amounts from your previous years rather than estimates and the result gets considerably closer to reality.
Working an example
An adult in one tax year
Take an adult in 2026 with enough tax payable to absorb the credit. The federal disability amount of $10,341 at 14 percent gives roughly $1,448. Add the provincial credit for their province and the disability tax credit worth for that single year lands somewhere above that, depending on where they live. Repeat the same arithmetic for each approved year.
A child under 18
For a child, the base plus the supplement is the starting point, so the federal side is materially larger. But the credit is still applied against a return, usually a parent’s, and the cap still applies to that return. A parent with modest tax payable may not be able to use all of it in the year it arises.
Retroactive years and the calculator
How far back a claim can go
The tax agency will generally reassess the ten previous calendar years. The practitioner’s answers on Form T2201 set the earliest year you are eligible for, and that date, not the ten-year window, is usually what limits a claim. Approval for 2019 onward means nine years, not ten.
Claiming past years with Form T1-ADJ
Retroactive claims are made using T1 adjustment requests. You file Form T1-ADJ for each year you want reopened, or submit the change through your online tax account, and those returns are reassessed one at a time. The calculator estimates what those reassessments are worth; the adjustment requests are what actually produce the money.
Why older years are often worth less
Older years carry lower indexed amounts and, for many claimants, lower income. Run the calculator year by year across multiple years and the pattern is common: the recent years carry most of the value and the earliest years add little. A single total for the whole period hides that.
Transfers to a spouse or supporting family member
The unused portion may transfer to a spouse or common law partner, or to a supporting person who provided basic necessities such as food, shelter, or clothing. This is why the calculator asks about transfers. In households where the claimant has little taxable income, the transfer is where nearly all of the money comes from, and leaving it out of the estimate makes the figure look far smaller than it is.
Who counts as an eligible family member
Eligible family members include spouses and common law partners, parents, grandparents, children, grandchildren, brothers, sisters, aunts, uncles, nieces and nephews, where that person supported the claimant. The transfer is claimed on the supporting person’s return for the same tax year, and the tax agency looks at who actually provided food, shelter, or clothing, not at who lives at the address.
Using the result
Treat the output as a planning range, not a specific refund. It is not tax advice, and we cannot promise a number that depends on approval and on your own tax history across multiple years.
What the number is not
It is not a refund confirmation, not an eligibility decision, and not a quote. Anyone offering you a firm dollar figure before Form T2201 has been approved and your returns reassessed is guessing at both the approval and your tax history.
Next steps after the DTC calculator
If the figure suggests it is worth pursuing, the next step is the DTC application.
Who provides the medical certification
A qualified medical practitioner, which can be a physician, nurse practitioner, occupational therapist, or another practitioner depending on the category, provides the medical certification that a severe and prolonged impairment in physical or mental functions leaves you markedly restricted in your ability to perform basic activities of daily living, or that an activity takes an inordinate amount of time. Vision is assessed with corrective lenses in place.
What the practitioner has to certify
Form T2201 must be completed by a qualified medical practitioner, and the impairment must have lasted, or be expected to last, a continuous period of at least 12 months. A condition that is severe but short is not eligible, no matter how disruptive it was at the time. The practitioner also sets the earliest year, which is what the disability tax credit calculated across retroactive years depends on.
What approval opens up
DTC approval then also opens the registered disability savings plan and the child disability benefit, which is paid with the Canada child benefit. For some people those two are worth more over time than the credit itself.
Common questions
Is this an official amount? No, it is an estimate. Can I do the paperwork myself? Yes, free of charge. How many past years can be reassessed? Generally the ten previous calendar years. What does usable amount mean? The credit limited by the tax you owed that year. Can a spouse claim the unused portion? Often yes, as a lump sum applied to their own tax return for that year. Does the DTC affect other benefits? Approval does not reduce provincial benefits, and it is the eligibility requirement for several other programs.
Why we will not quote you a figure
You will see firms advertise a typical retroactive refund range. We do not, because the number depends entirely on your own tax payable in each of the previous years, and we have not seen your notices of assessment. A range pulled from other people’s files tells you nothing about your own.
Final thoughts
A DTC calculator is useful for one thing: deciding whether the application is worth the effort. It cannot tell you what you will receive, because that depends on an approval you do not have yet and on tax years that have not been reassessed.
Canadian Benefits Association prepares Disability Tax Credit paperwork and nothing else. Thirteen years, 100 percent DTC practice, nothing to pay upfront, and you pay only if a refund is issued. Our registrations are public: representative ID GPF6SB, EFILE K7112, Ontario Corporation 002381754, Business Name Registration 1001179177. We are a BBB accredited business.
You can also do all of this yourself, free of charge. The calculator on this page works the same either way.
