Profit / loss = (Sell price − Buy price) × Shares − Brokerage fees. Simple. What you walked away with minus what you put in minus what it cost to trade.
Percentage return = Profit ÷ Total invested × 100. If you invested $5,000 and made $1,500, that's a 30% return — regardless of how many shares you held.
Annualised return (CAGR) is the tricky one. A 60% total return over 6 years is not 10% per year — it's 8.1%, because of compounding. The formula is: (Sell value ÷ Buy value)^(1 ÷ years) − 1. This lets you compare any investment against alternatives on the same time basis.
Why the index comparison matters: Most active share picks underperform a simple index fund (like the ASX 200 or S&P 500) over long periods after fees and taxes. The index comparison shows what you would have made by just buying the market — with zero effort, zero stock-picking risk, and usually lower fees.
Capital gains tax: In Australia, shares held over 12 months get a 50% CGT discount — only half the profit is taxed at your marginal rate. Short-term gains are taxed in full. The CGT estimate above is indicative — use the full CGT Calculator for your exact situation.
Dividend income is not included in this calculator — it measures capital gain only. For dividend-focused analysis, see the Dividend Growth Calculator.