Interactive Tools

Learn economics by doing it

Free tools built to make economic concepts tangible. Simulate markets, calculate your paycheck, model macro scenarios, and plan for college — all in your browser.

Core Tools

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Portfolio Simulator

Build a portfolio across stocks, bonds, real estate, crypto, and cash. Watch 30 years of real market history — dot-com crash, 2008, COVID — play out year by year with live event commentary.

Investing Launch →

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First Paycheck Calculator

Enter your hourly rate or salary and see exactly where your money goes — federal income tax, state tax, Social Security, Medicare. Generates a real-looking pay stub and calculates your Roth IRA potential.

Tax & Income Calculate →

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Economic Dashboard

Live inflation rate, Fed funds rate, unemployment, GDP growth, S&P 500, 10-year Treasury yield, and Bitcoin price — all in one place with plain-English explanations of what each number means for students.

Macro Indicators Open →

Advanced Simulators

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Advanced Financial Simulator — 5 Modes

The full suite: historical market replay, Monte Carlo probability simulation, quantitative strategy back-testing, macro scenario modeling, and college funding planner. All in one dark-mode dashboard.

Full Suite

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Monte Carlo Simulator

Run up to 10,000 randomized investment scenarios using Box-Muller normal distribution sampling. See the full probability distribution of outcomes — median, 10th percentile, 90th percentile — and the chance of doubling your money or losing it.

Statistics · Probability

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Quant Strategy Back-Tester

Test algorithmic trading strategies against 30 years of historical data. Compare moving average crossover (golden cross / death cross), momentum investing, risk parity, and dollar cost averaging. Shows Sharpe ratio, max drawdown, and performance vs. buy-and-hold baseline.

Algorithmic Trading · Quant Finance

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Macro Scenario Builder

Set inflation, Fed funds rate, GDP growth, market stress, and dollar strength. Load presets like 2008 Financial Crisis, COVID 2020, 1970s Stagflation, or 90s Bull Run. See how different portfolios respond to each macro environment.

Macroeconomics · Scenario Analysis

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College Funding Planner

Enter tuition costs, years until college, current savings, monthly contribution, and expected scholarships. See your funding gap, what loan payments would look like, and a savings vs. cost trajectory chart over time.

College Planning · Personal Finance

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Historical Market Replay (Advanced)

The full-featured version of the portfolio simulator with individual allocation sliders for each asset class, adjustable speed, crash event commentary, and per-asset return breakdowns. Watch 1995 to 2026 play out year by year.

Market History · Portfolio Theory

A note on these tools

All tools are free, require no account, and work entirely in your browser. They use historical market data and mathematical models to illustrate economic concepts — not to provide financial advice. Past performance doesn't guarantee future results. Built by Tobias Velez, Walter Johnson High School.