Use clear assumptions
Every projection depends on inputs such as starting amount, contribution frequency, expected return, time horizon, asset choice and compounding behavior.
This page explains the assumptions, data handling, formulas, and limitations behind WhatIfInvested calculators and simulations, so users can interpret results with more confidence.
WhatIfInvested is built for educational planning. The tools are meant to help users compare scenarios, not promise outcomes or recommend a specific investment.
Every projection depends on inputs such as starting amount, contribution frequency, expected return, time horizon, asset choice and compounding behavior.
A historical backtest shows what happened over a selected period. A forward projection estimates what could happen under assumptions selected by the user.
Taxes, fees, spreads, inflation, behavioral decisions, account rules and real-world execution can change actual results.
Where historical simulations are available, WhatIfInvested uses daily price series from reputable market data providers or public datasets. When adjusted prices are available, they may include events such as dividends, distributions, splits, and other corporate actions.
Historical data can still contain gaps, provider revisions, ticker changes, delistings, currency differences, or missing periods. For that reason, backtests should be treated as educational approximations rather than official performance records.
For assets with limited history or incomplete data, the simulation window may be shorter than the user expects. This is especially relevant for newer ETFs, crypto assets, and securities that changed tickers.
The exact workflow depends on the tool, but most simulations follow a clear process from user input to final result.
The user selects values such as asset, amount, dates, contribution schedule, annual return or compounding frequency.
The calculator models when contributions are added and how often growth or market prices are applied.
The tool estimates ending value, total contributions, growth, returns, and visual breakdowns.
Charts, tables and summaries help users compare scenarios and understand what drove the result.
Dollar-cost averaging models recurring investments made on a schedule, such as weekly, bi-weekly, monthly or yearly. Lump sum investing models a larger amount invested earlier. Each approach can produce different results depending on market path, volatility and timing.
When comparing DCA and lump sum, the simulator focuses on the selected assumptions and period. It does not claim one strategy is always better. In rising markets, investing earlier can have an advantage. In volatile or falling markets, spreading contributions can reduce timing regret and make the process easier to follow.
For deeper strategy comparison, use the investment simulator and read the lump sum vs DCA guide.
Depending on the tool, results may not include all real-world variables. Users should be careful when comparing projections with actual investment account outcomes.
Use the methodology alongside the tools themselves. Comparing calculators often gives a clearer picture than relying on one number.
WhatIfInvested tools are designed for education and planning. They do not provide personalized investment, legal, tax or financial advice. Use the results to ask better questions, compare assumptions and understand tradeoffs before making real decisions.