Assumptions and methodology
Effective 5 September 2026. The version of the tax data and projection assumptions applied to any result is recorded with it, under About in the app.
- How your plan is calculated
- Everything is calculated on your device, one year at a time, from what you enter. There is no market data feed and no connection to any financial institution.
- Tax and benefit rules
- Federal and provincial brackets and the main personal credits, CPP and OAS amounts, the OAS clawback, and RRIF and LIF minimums come from published government sources. The version in use is shown under About. The tables are refreshed every January, when brackets index and benefit amounts move, and again every July, because a province can change its rates mid-year.
- What your investments earn
- Return assumptions come from the Projection Assumption Guidelines, published each year by the Institute of Financial Planning and FP Canada Standards Council. Canadian financial planners use the same guidelines, and they are set deliberately to be free from bias rather than optimistic or cautious. Vidda applies the risk profile you choose across the guideline asset classes, then subtracts the fees you pay for owning the investments in each account, from what you said is in it, or the guidelines' own typical figure until you say. The rate you see is what you would keep. Guaranteed deposits skip the blend and earn the guideline short-term rate, because a GIC is not a portfolio. You can replace any rate with your own. While an account follows the guidelines Vidda shows you the figure it is using, so you see it before you change it, and clearing the field again puts the account back on it.
- Inflation, and how long your plan runs
- Inflation is 2.1% unless you change it, also from the guidelines. Your plan runs to age 95 by default. That age is Vidda's rather than the guidelines': they publish a separate planning age for a man, for a woman and for each kind of couple, and 95 sits between the two single figures at 65. Outliving your plan is the one mistake you cannot fix later, so under Plan runs to age Vidda shows you their table and you can take the age that fits you.
- The shaded band on Home
- Not a probability. It is the same plan run with every growth rate 1.5 points cooler and hotter, drawn as one band from the cool run to the hot one, to show how much your answer depends on an assumption nobody can know. The shift is deliberately large, and nothing else moves: the same spending, the same taxes, the same plan, with only the growth assumption shifted.
- The stress test
- A thousand runs, each with its own sequence of good and bad years, its own inflation, its own answer for how long you live and its own late life care and medical costs, reporting how many lasted. Every run also assumes you would react: spending drops 10% in any year the portfolio sits 20% or more below its peak, and there is no way to turn that off, so the share that lasted is higher than it would be for a plan that never flinches. It measures how much bad luck your plan absorbs, not the chance of anything in particular happening. The guidelines' own data appendix supplies how much returns vary year to year. How much inflation varies, and how it moves with returns, are Vidda's own figures with no published guideline behind them. The historical setting replays real sequences in ten-year blocks and is a sensitivity check that sits outside the guidelines rather than an application of them.
- What this is not
- Estimates, not advice, and not a forecast. Vidda does not model everything, and the list of what it leaves out is published rather than summarised.