What this calculator does
Maple Investor replays history for a Canadian saver. You choose an asset, a starting lump sum, a monthly contribution and a date range, and the calculator walks forward one month at a time, adding your deposit and applying that month's market return. The result is the portfolio value you would have had, shown both in nominal dollars and in purchasing power.
Four building blocks are available: the S&P 500 converted into Canadian dollars, the S&P/TSX Composite, the S&P/TSX 60 and gold priced in CAD. Because every series is expressed in Canadian dollars, the comparison reflects what a Canadian household would actually have experienced, including currency swings on foreign holdings.
How the monthly calculation works
Each month, the calculator adds your contribution to the balance and then multiplies by one plus that month's growth rate. This is the standard dollar-cost averaging pattern: money goes in on a schedule regardless of whether markets just rose or fell. Cash deposited is tracked separately so you can see how much of the final balance is your own money and how much came from growth.
If you tick the inflation option, your monthly deposit rises every twelve months in line with Canadian CPI, which mimics a saver who raises contributions as living costs and wages increase. Leave it off and the deposit stays flat in nominal dollars.
Nominal versus real results
A million dollars in 2050 will not buy what a million dollars buys today. That is why every result is displayed twice. The nominal figure is the number you would see in your account. The real figure divides by the change in the Bank of Canada consumer price index since your start month, giving you the same balance in the purchasing power of the first day.
The gap between the two annualised returns is the quiet cost of inflation. During calm decades it is small; during the high-inflation 1970s and early 1980s it consumed most of the nominal gains from many assets.
Taxes, accounts and what is not modelled
The tax setting is deliberately simple. Selecting TFSA applies an estimated 0.30 percentage point yearly drag to the S&P 500 to represent the 15 percent U.S. withholding tax on dividends that a TFSA cannot recover. Registered and non-registered accounts differ in many other ways, such as capital gains, contribution room and foreign tax credits, which are not modelled here.
Fees, trading costs, bid-ask spreads and fund management expense ratios are also excluded, and so are personal taxes. Real portfolios will usually come out slightly below the figures shown, so treat the output as an upper-bound illustration rather than a forecast.
Where the numbers come from
The dataset is static, monthly and stored with this site. Modern index returns are used directly. Longer histories are rebuilt from public sources such as Robert Shiller's market dataset, Statistics Canada tables, the Bank of Canada and exchange-rate records, and are best read as careful estimates. The data notes further down this page explain which segments are proxies, for example the TSX Composite standing in for the TSX 60 before the fund existed.
Past performance never guarantees future results. Use the calculator to build intuition about volatility, compounding, currency effects and inflation, then speak with a licensed professional before acting.