What ROI means
ROI stands for return on investment, and it answers one plain question: how much did I make relative to what I put in? Because it’s expressed as a percentage, it lets you compare deals of wildly different sizes at a glance. A side hustle that returned $500 on $1,000 spent had the exact same ROI as an ad campaign that returned $5,000 on $10,000 — both landed at 50%.
This calculator runs entirely in your browser. Nothing you type is stored or sent anywhere: enter the cost and the final value, and you immediately get the net gain, the ROI, and — if you add the number of years — the annualized ROI.
How to use the calculator
- Initial investment (cost): everything you put in. That means not just the purchase price but fees, shipping, repairs, or any related expense. The more complete this figure, the more honest your result.
- Final value or return: what you got back, or what the investment is worth today. If you sold, use the net sale price; if you still hold it, use its current market value.
- Period in years (optional): how long you held the investment. You only need it if you want the annualized ROI.
The formula
Simple ROI is calculated like this:
ROI (%) = (net gain ÷ investment) × 100
where the net gain = final value − investment. If that comes out negative, you didn’t profit — you lost that percentage.
To compare investments held for different lengths of time, use the annualized ROI, which restates the total return as an equivalent yearly rate:
Annualized ROI (%) = ((final value ÷ investment)^(1 ÷ years) − 1) × 100
Worked example
You invest 1,000 and after 2 years you receive 1,500.
- Net gain: 1,500 − 1,000 = 500
- Simple ROI: (500 ÷ 1,000) × 100 = 50%
- Annualized ROI: (1,500 ÷ 1,000)^(1 ÷ 2) − 1 = 1.5^0.5 − 1 = 22.47% per year
A 50% return sounds spectacular, but spread over two years it works out to 22.47% a year — still solid, just less dazzling. That gap is exactly why the annualized figure matters.
Simple ROI vs. annualized ROI
| Aspect | Simple ROI | Annualized ROI |
|---|---|---|
| What it measures | Total return for the period | Equivalent return per year |
| Accounts for time | No | Yes |
| When to use it | A single, one-off deal | Comparing investments of different lengths |
| Example (1,000 to 1,500 in 2 years) | 50% | 22.47% |
Limitations
ROI is powerful because it’s simple, but that same simplicity hides things that matter. It ignores risk: a 30% return on crypto and a 30% return on a bank CD show the same ROI but not the same odds of actually happening. It ignores inflation: if your money grew 10% in a year when prices rose 8%, your real gain was barely 2%. And it barely accounts for time unless you use the annualized version. Treat ROI as a first filter, not a final verdict.
Frequently asked questions
What counts as a good ROI?
It depends on context. In the stock market, the S&P 500 has historically averaged roughly 7-10% per year (already annualized), so beating that consistently is considered good. In your own business the bar is usually higher, because you’re taking on more risk and labor. The practical rule: always compare against a safe alternative, such as a savings certificate.
How is ROI different from IRR?
ROI looks at the total money in versus money out. IRR (internal rate of return) accounts for the exact timing of every cash flow when there are multiple ins and outs over time. For a single investment with one payout, annualized ROI and IRR give the same answer. Once there are interim deposits or withdrawals, IRR is the more accurate measure.
How do I annualize an ROI I already have?
If you know the final value and the investment, apply the annualized formula directly. If you only have the total ROI, first turn it into a factor: a 50% ROI, for instance, is a factor of 1.5. Then raise that factor to the power of 1 ÷ years, subtract 1, and multiply by 100.