Free Investment Calculators & Tools
Every tool is free, runs in your browser, and shows its methodology. No signup, no paywall.
Financial Calculators
Investment Time Machine
NewWhat if you had invested in 2010? Replay real history.
Rebalancing Calculator
NewExact buy/sell orders — or invest new money without selling.
Withholding Tax Impact
NewVOO vs CSPX: the real cost of US dividend withholding.
Compound Interest
Growth projections with monthly contributions.
Retirement Nest Egg
How much you need to retire, with the 4% rule.
Retirement Drawdown
How long your portfolio lasts in retirement.
FIRE Calculator
FI number, Coast FIRE age, and your progress.
Fee Drag
How expense ratios compound against you.
Lump Sum vs DCA
Invest at once or average in — with real data.
S&P 500 Returns
Historical returns since 1928, any window.
Dividend Income
Project income with DRIP, growth, and taxes.
Inflation Impact
What inflation does to your purchasing power.
Emergency Fund
Right-size your safety net for your risk profile.
ETF Analysis (326 funds)
Portfolio Backtester
Up to 5 portfolios, real monthly data.
ETF Screener
Filter the full catalog.
Compare ETFs
Side-by-side, up to 4 funds.
Overlap Analyzer
Holdings you own twice.
Portfolio X-Ray
True exposure and concentration.
Correlation Matrix
How your funds move together.
Risk vs Return Map
CAGR against volatility.
Model Portfolios
Curated allocations to start from.
Prefer to start from a proven allocation?
Browse model portfolios