ROI Calculator

Return on investment is the simplest way to judge whether something paid off: how much you got back relative to what you put in. It works for stocks, a side business, a marketing spend, or a home improvement.

How it works

ROI = (amount returned − amount invested) ÷ amount invested × 100.

ROI expresses your net gain as a percentage of the amount invested, which lets you compare opportunities of different sizes on equal terms. A $500 gain on $5,000 (10%) and a $5,000 gain on $50,000 (10%) are equally efficient uses of capital, even though the dollar amounts differ.

ROI's main blind spot is time — it doesn't say how long the return took. A 50% return over one year is far better than 50% over ten. For time-adjusted comparisons, pair it with the CAGR calculator.

ROI = (amount returned − amount invested) ÷ amount invested × 100

Worked examples

• Invested $5,000, returned $7,500 → +50.0% ROI, $2,500 net gain

  ($7,500 − $5,000) ÷ $5,000 = 0.50 = +50%, a $2,500 gain on the original stake.

• Invested $10,000, returned $9,000 → −10.0% ROI, $1,000 loss

  A negative ROI signals a loss: ($9,000 − $10,000) ÷ $10,000 = −10%.

Tips & gotchas

• ROI ignores time — always note the holding period, since a 30% return over one year crushes 30% over five.
• Include all costs in the 'invested' figure (fees, commissions, upgrades) so the ROI reflects your true outlay.
• Use ROI to rank competing uses of money, but use CAGR when the time horizons differ — that's the apples-to-apples comparison.
• A negative ROI isn't always a failure if it bought something else of value (experience, a strategic foothold) — just don't confuse that with a financial return.

FAQ

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