How we calculate
Visible assumptions. Checkable formulas. Clear limitations.
Every result is only as useful as its assumptions. This release makes those assumptions visible. Independent professional financial review remains pending.
Calculation standards
- Use Canadian conventions where relevant, rather than silently importing U.S. assumptions.
- State which loan types, account rules and fees the calculation includes and excludes.
- Keep intermediate calculations unrounded. Display currency to two decimal places, except where a chart uses compact axis labels.
- Reject missing or invalid inputs instead of showing a stale answer.
- Separate a result during a mortgage term from a lifetime projection at an unchanged rate.
- Keep source-check dates separate from professional-review status.
What is checked
Automated calculation checks cover an independent mortgage-payment reference, principal conservation across payment frequencies, zero-interest payments, prepayment savings, full payoff by a lump sum, insurance-tier boundaries, the C$1.5 million minimum-down-payment threshold, zero-return savings, savings-goal contributions, insufficient debt payments and equal after-tax RRSP/TFSA results at equal tax rates.
These tests check the model. They do not certify a lender quote or establish that every possible Canadian financial circumstance is covered. A targeted technical check covered FCAC payment frequencies and prepayment scope, CMHC insured-loan tiers, OSFI stress-test guidance, CRA account assumptions, Alberta registration fees and Toronto municipal tax exceptions. Technical checks do not replace qualified professional review or certify a lender quote.
Sources and changes
Each calculator links to relevant official sources and carries a source-check date. A source link supports the underlying rule or context; it does not imply government endorsement or validation of this implementation. Annual limits, rates and legislation will require ongoing review as additional tax and registered-account tools are added.
The initial calculators use user-supplied rates. They do not fetch live market rates, calculate current tax brackets or claim a guaranteed return.
Review responsibilities before launch
| Area | Needed review |
|---|---|
| Mortgage models | Canadian mortgage professional; lender compounding, rounding and payment-frequency comparisons. |
| Tax and registered accounts | Qualified Canadian tax or financial-planning reviewer; contribution eligibility, assumptions and exclusions. |
| Engineering | Calculation boundaries, accessible interactions, mobile browser checks, privacy and regression checks. |
Explore the models
See our dated rule checks and current independent-review status.