Free tools · No signup · No spreadsheet required
Primed Investor is a set of fast, free calculators for the decisions that actually move a portfolio: how compounding builds wealth, how much to risk on a single trade, and what reinvested dividends do over decades.
Start with compounding Size a tradeEach calculator updates live as you type, explains the math underneath, and works on your phone. Nothing is stored, tracked, or sold.
Project how an initial investment plus monthly contributions grows over time, with a year-by-year chart of the curve.
Open calculator → RiskTurn your account size, risk tolerance, and stop-loss into an exact share count — the discipline most losing traders skip.
Open calculator → IncomeSee what reinvesting dividends does over decades, including dividend growth and share price appreciation.
Open calculator →Most investing mistakes are not stock-picking mistakes. They are arithmetic mistakes — underestimating what compounding does over 20 years, risking too much on one position, or ignoring what reinvested dividends contribute to total return.
These tools cover the three questions every investor faces: how fast does money grow (compound interest), how much should I put into one idea (position sizing), and what does income reinvestment add (DRIP). Answer those three with real numbers instead of gut feel, and you are ahead of most of the market.