Understanding your ROI result
ROI and annualized return answer different questions: total profitability versus time-adjusted performance. Both are needed to compare investments fairly.
| Metric | What it tells you |
|---|---|
| ROI | Total percentage gain over the whole holding period, ignoring its length |
| Annualized return | The constant yearly compound rate equivalent to the total gain (same as CAGR) |
| Positive ROI, low annualized | Profitable but slow — a long holding period diluted the yearly rate |
| Negative ROI | The amount returned was less than the amount invested |
- The calculation assumes a single investment and a single exit value; dividends, rents or other interim cash flows are only captured if added into the amount returned.
- ROI is pre-tax and ignores inflation; real (inflation-adjusted) returns are lower than nominal ones.
- A high past ROI does not indicate future performance, and comparing ROIs without considering risk can be misleading; investment decisions merit advice from a licensed professional.
What is ROI?
Return on investment (ROI) measures the profitability of an investment as the net gain divided by the cost: ROI = (amount returned − amount invested) ÷ amount invested, expressed as a percentage. It appears throughout corporate finance, marketing and personal investing because it reduces any project to a single comparable percentage. Standard finance texts treat it as the entry-level profitability ratio.
ROI's chief limitation is that it says nothing about time. An investment that returns 35% over three years and one that returns 35% in one year have identical ROI but very different performance. The annualized return — the constant yearly rate that would compound to the same total — corrects this. It is computed as (returned ÷ invested)^(1/years) − 1 and is mathematically the same quantity as CAGR.
ROI also ignores risk and intermediate cash flows. Two projects with equal ROI can carry very different uncertainty, and a project that pays cash along the way is not distinguished from one that pays only at the end. Metrics such as IRR (internal rate of return) handle intermediate cash flows; ROI remains the right tool for simple invest-once, exit-once comparisons.
How to use this ROI calculator
- Enter the total amount invested, including purchase costs and fees where known.
- Enter the total amount returned — the final value or sale proceeds, net of selling costs where known.
- Enter the holding period in years to get the annualized return; leave it at zero to see simple ROI only.
- Read the ROI percentage, the net gain in currency, and the annualized return for comparing across time horizons.
The ROI formula
Simple ROI divides the net gain by the amount invested. The annualized return converts the total growth multiple into a constant yearly compound rate over the holding period.
Worked example: $10,000 invested that returns $13,500 after 3 years gives ROI = (13,500 − 10,000) ÷ 10,000 = 35%, a net gain of $3,500. The annualized return is (13,500 ÷ 10,000)^(1/3) − 1 = 1.35^0.3333 − 1 ≈ 10.52% per year — the constant rate that compounds to the same 35% over three years.
Common mistakes
- Comparing ROIs over different holding periods without annualizing — 35% over three years is about 10.5% per year, not 35%.
- Confusing amount returned with net gain; the calculator expects the total final value, not the profit.
- Leaving out fees, commissions and taxes, which reduce the true amount invested-versus-returned spread.
- Ignoring interim cash flows such as dividends, which belong in the amount returned.
- Averaging yearly ROIs arithmetically; compounding requires the geometric mean, which the annualized figure provides.
よくある質問
How is ROI calculated?
ROI equals the net gain divided by the amount invested, times 100: ROI = (returned − invested) ÷ invested × 100%. For example, investing $10,000 and receiving $13,500 back gives ROI = 3,500 ÷ 10,000 = 35%. The figure ignores how long the money was invested, which is why an annualized version is often reported alongside it.
What is the difference between ROI and annualized return?
ROI is the total percentage gain over the entire holding period; the annualized return is the constant yearly compound rate that would produce the same total. A 35% ROI earned over 3 years annualizes to about 10.52% per year, while the same 35% in one year annualizes to 35%. Annualizing makes investments with different durations directly comparable.
What is a good ROI?
It depends on the time period and the risk taken. As context, US large-cap equities have returned roughly 10% per year on average over the long run, so an annualized return near that level matches broad market history, while short-term ROIs can be far higher or lower. An ROI should always be judged per year and against the risk and alternatives, not as a raw total.
Is ROI the same as CAGR?
Not quite. ROI is the total un-annualized gain percentage. CAGR (compound annual growth rate) is the annualized version — identical to the annualized return this calculator reports: (end ÷ start)^(1/years) − 1. For a one-year holding period ROI and CAGR coincide; over longer periods CAGR is smaller than the total ROI.
Does ROI account for risk or inflation?
No. ROI is a pure arithmetic ratio of money out to money in. It does not adjust for the risk taken, the volatility endured, taxes, or inflation's erosion of purchasing power. Risk-adjusted measures (such as the Sharpe ratio) and real returns address those dimensions; ROI is best used as a quick, comparable summary rather than a complete evaluation.
参考文献
- Brealey RA, Myers SC, Allen F. Principles of Corporate Finance (13th ed.). McGraw-Hill, 2020 — investment criteria and returns.
- Bodie Z, Kane A, Marcus AJ. Investments (12th ed.). McGraw-Hill, 2021 — rates of return, arithmetic vs geometric averages.
- US Securities and Exchange Commission (SEC). Investor.gov — assessing investment performance. investor.gov.
- Federal Reserve Bank of St. Louis. S&P 500 historical returns. FRED Economic Data (fred.stlouisfed.org).
- CFA Institute. Quantitative methods — time value of money and return measurement. cfainstitute.org.