Free tools
Compound interest
Investing
Business & pricing
Personal finance
Benefits & fixed income
Currency
Annual return 7.0%
Time horizon 30 yrs
Compounding
Show in today's money
Projected balance after 30 years
$691,150You put in
$190,000
Interest earned
$501,150
Growth multiple
3.64×
ContributionsCompound interest
Projections assume a constant annual return with steady contributions — real markets don't move in straight lines. Currency is a display setting; no live exchange rate is applied. Educational estimate, not investment advice.
Bring your own API
Track SPY, VOO, QQQ and any ETF with live data — your key, your rules
Plug in your own market data key (Polygon, Finnhub, Alpha Vantage, Twelve Data, or Tiingo — all have free tiers) and the ETF compare tool pulls real historical prices for the tickers you care about.
What can I do with a key?
- Auto-pull weekly price history for SPY, VOO, QQQ, DIA, IWM, VTI, or a custom ticker
- Compare "market truth" vs your assumed rate side-by-side
- Sign in to save your key — encrypted at rest, readable only by you