ROI calculator (return on investment)

What is an ROI calculator?

An ROI (return on investment) calculator is a free online tool that measures how much money an investment made or lost relative to what you put in. You enter the initial investment and the final value, and it returns the net gain in dollars and the ROI as a percentage. If you also enter how long you held the investment, it works out the annualized ROI — the equivalent steady yearly return — so you can compare deals that ran for different lengths of time on a level footing.

ROI is one of the most widely used performance measures in finance precisely because it is simple: a single percentage that says how efficiently your money worked. It applies to almost anything with a cost and a payoff — stocks, real estate, a marketing campaign, or a piece of equipment.

How does it work?

The calculator takes the initial investment and the final value and finds the net return by subtracting one from the other. Dividing that net return by the initial investment and multiplying by 100 expresses the gain as a percentage of what you originally committed. When you supply a holding period in years, the tool converts the total return into an annualized figure using compounding, which answers the question “what constant yearly return would have produced this same result?”

Formula

The core ROI figures are:

$\text{Net return} = \text{Final value} - \text{Initial investment}$

$\text{ROI} = \frac{\text{Final value} - \text{Initial investment}}{\text{Initial investment}} \times 100\%$

When a holding period is provided, the annualized ROI is:

$\text{Annualized ROI} = \left( \left( \frac{\text{Final value}}{\text{Initial investment}} \right)^{\frac{1}{n}} - 1 \right) \times 100\%$

where $n$ is the number of years the investment was held.

Worked example

You invest $1,000 and it grows to $1,200:

$\text{Net return} = 1200 - 1000 = 200$

$\text{ROI} = \frac{1200 - 1000}{1000} \times 100\% = 20\%$

So the net return is $200 and the ROI is 20%.

If that same growth happened over 2 years, the annualized ROI is:

$\text{Annualized ROI} = \left( \left( \frac{1200}{1000} \right)^{\frac{1}{2}} - 1 \right) \times 100\% \approx 9.5445\%$

An annualized 9.5445% return, compounded over two years, is what turns $1,000 into $1,200.

ROI vs annualized ROI

The total ROI stays the same regardless of how long you held the investment, but the annualized ROI shrinks as the holding period lengthens, because the same total gain is spread across more years.

Notes

ROI in its basic form ignores the timing of cash flows and the effect of time, which is why the annualized figure matters when comparing investments of different durations. For a return that already builds in a fixed number of periods, the annualized ROI here is the same idea as a CAGR calculator, and it pairs naturally with a compound interest calculator when you want to project growth forward. Basic ROI also excludes taxes, fees, and inflation — subtract those from the final value if you want a truer picture.

FAQ

What is a good ROI?

It depends on the risk and the time frame. Historically, a diversified stock portfolio has returned roughly 7–10% per year on average, so a long-run annualized ROI in that range is often considered solid. Short-term or higher-risk bets are usually expected to return more to justify the risk.

Can ROI be negative?

Yes. If the final value is less than the initial investment, the net return and the ROI are both negative, meaning you lost money. For example, $1,000 falling to $800 is a net return of −$200 and an ROI of −20%.

Why is the annualized ROI lower than the total ROI?

Because annualized ROI spreads the total gain across the number of years you held the investment and accounts for compounding. A 20% total gain over two years is only about 9.54% per year, since each year’s growth compounds on the last.