A useful retirement tax calculator should model tax year by year and by spouse. It should distinguish fully taxable registered withdrawals and interest from capital gains using adjusted cost base, while also considering pension splitting and OAS recovery.
Retirement income is not taxed the same way
| Source | Typical modeling treatment |
|---|---|
| RRSP/RRIF withdrawals | Generally included in taxable income. |
| Interest / GIC income | Generally included as interest income as earned. |
| Capital-gains investments | Tax is tied to realized gains; ACB is needed to estimate the gain. |
| TFSA withdrawals | Generally tax-free and not included in taxable income. |
| CPP / OAS | Taxable benefits; OAS may also be subject to recovery tax at higher income. |
Why adjusted cost base matters
For a non-registered capital investment, the sale proceeds are not the same thing as taxable income. The capital gain is generally based on proceeds minus adjusted cost base and eligible disposition costs. If only part of a holding is sold, ACB must be allocated appropriately. A portfolio can also have ACB above current market value, which represents an unrealized loss rather than a taxable gain.
Household tax optimization
For couples, tax is calculated individually even though retirement spending is a household decision. Eligible pension-income splitting can shift taxable income between spouses. The optimal split can change annually and can affect OAS recovery and retirement-related credits.
What the planner calculates
The planner uses 2026 federal and provincial/territorial brackets and selected retirement credits as its base-year model, indexes future planning assumptions, estimates OAS recovery, and compares tax-aware withdrawal strategies. It is not tax-return software and does not model every deduction, credit or special circumstance.
Estimate your retirement tax path
Compare lifetime tax, annual taxable income and after-tax estate under different retirement strategies.