Why this tool exists
Traditional compound-interest calculators are useful for quick math, but they hide the real experience of investing. Markets do not move in a straight line. Dividends change, taxes matter, asset correlations shift, and withdrawals can create sequence-of-return risk. Portfolio Modeler is designed to make those moving parts more visible.
The simulator is not trying to predict the exact future value of a portfolio. It is meant to help visitors explore questions like: How wide is the range of outcomes? What would a weak-return path look like? How much final-year dividend income might the portfolio generate? What happens if contributions become withdrawals?
What makes it different
- It models each ticker separately instead of treating the whole portfolio as one blended return.
- It uses covariance between holdings so diversification can show up in the simulation.
- It separates reinvested-dividend and no-DRIP return assumptions.
- It includes practical planning inputs like tax drag, dividend taxes, contribution growth, withdrawals, and rebalancing.
Who it is for
The site is intended for self-directed investors, students, and planners who want to understand how assumptions change a long-term portfolio projection. It can be useful when comparing a diversified ETF allocation, a dividend-income approach, a retirement withdrawal plan, or a concentrated growth sleeve.
Portfolio Modeler is especially useful when the question is about risk rather than only return. A visitor can compare downside percentiles, median outcomes, upside ranges, drawdowns, final-year dividend income, and goal probabilities using the same inputs on one screen.
How the educational material supports the calculator
The simulator is paired with methodology notes, an investor guide, example scenarios, a glossary, and articles. Those pages explain how to read the output, how dividend reinvestment changes return assumptions, why drawdowns matter, and why a portfolio model should be interpreted as a range rather than a guarantee.
New pages are added as the tool develops so the site remains useful as an educational resource, not only as a calculator interface.
Responsible use
Portfolio Modeler is an educational planning tool. It does not provide personalized investment recommendations, and it does not know a user's full financial situation. Results should be reviewed alongside other planning work and, when appropriate, with a qualified financial, tax, or legal professional.