How to use the ROI calculator
- Enter everything you put into the investment in Investment cost. 0 is allowed, but then no ROI can be shown.
- Choose how you want to enter the result: Use amount returned or Use net profit.
- Enter the total you got back in Amount returned, or the profit left over in Net profit. A loss is written with a minus sign, such as -400.
- Select Calculate to see ROI, net profit, amount returned and the break-even return.
- Select Reset example to go back to the values shown when the page opened.
The value you do not choose is never used. If you pick Use amount returned, whatever is left in the net profit field is not passed to the calculation at all, so a stale figure cannot quietly change your result.
The values shown when the page opens are a hypothetical example chosen to show how the calculation works. They are not a real product return or a market forecast. This calculator holds no return, tax or fee figures of its own.
What ROI means
ROI is short for return on investment. It compares the net profit with the investment cost and states the result as a percentage. Putting in 1,000 and getting back 1,200 leaves a net profit of 200, which is 20% of the cost, so the ROI is 20%.
Because it is a single division, ROI can be used for anything you can put a cost and a result against: a share purchase, a piece of equipment, a marketing campaign or a side project. The unit never enters the calculation, so you only need both figures in the same currency.
ROI does not reflect time. The formula has no place for a period, so a gain made in a month and the same gain made over a decade are indistinguishable. That is the single most important limit to keep in mind when comparing investments with it.
ROI formula
These are the formulas this calculator uses. Following them in order lets you check the result by hand.
ROI(%) = ( net profit ÷ investment cost ) × 100
- Investment cost: everything you put in (0 or more)
- Net profit = amount returned − investment cost
- Amount returned = investment cost + net profit
- Break-even return = investment cost
The two ways of entering the result are the same equation read from either end, which is why the answer is identical whichever one you choose. The break-even return is always equal to the investment cost, because that is the point where the net profit and the ROI are both exactly 0.
An investment cost of 0 cannot produce an ROI. There is nothing to divide by, so the calculator shows the net profit and the amount returned but leaves the rate uncalculated rather than inventing a 0% or an infinity. Intermediate values are never rounded; only the numbers on screen are tidied up for display.
Worked example
These are the same values the calculator shows when the page opens. Both figures are a hypothetical example, not a real product return or a market forecast.
- Investment cost 1,000, amount returned 1,200
- Net profit = 1,200 − 1,000 = 200
- ROI = (200 ÷ 1,000) × 100 = 20%
- Break-even return = 1,000, the same as the investment cost
Switching to Use net profit and entering 200 against the same 1,000 gives exactly the same ROI of 20% and rebuilds the amount returned as 1,200. A loss works the same way: entering −400 as the net profit against a cost of 1,000 gives an amount returned of 600 and an ROI of −40%.
ROI vs CAGR / annualized return
ROI, an annualized return and CAGR answer different questions, so it helps to know which one you actually need.
- ROI (this page) asks how much came back compared with what went in. No period is involved, so results from different lengths of time are not comparable on this scale.
- An annualized return restates the same gain as a per-year rate, which is what you need when one investment ran for six months and another for six years.
- CAGR takes a beginning value, an ending value and a period, and smooths the whole change into one equivalent annual rate.
- Neither is IRR or XIRR. When money went in and out at several different dates, those measures are the ones that take every amount and its date into account, and this site does not provide them.
A worked comparison: a 20% ROI earned in one month is a very different result from a 20% ROI earned over ten years, yet ROI shows both as 20%. To separate them, use the Investment Return Calculator or the CAGR Calculator, both of which take a period as an input.
Assumptions and limitations
- ROI is net profit compared with investment cost, stated as a percentage.
- ROI does not reflect time. A gain made in a month and the same gain made over ten years look identical.
- Comparing periods of different lengths needs an annualized return or CAGR instead.
- ROI is not IRR or XIRR, and this calculator does not provide them.
- An investment cost of 0 leaves nothing to divide by, so no rate is shown rather than a made-up one.
- A loss larger than the investment cost is refused, because an amount returned below 0 has no meaning here.
- Taxes are not automatically included.
- Fees are not automatically included.
- Inflation is not automatically included.
- Exchange rates are not automatically included. No currency conversion happens anywhere on this page.
- Market data is not automatically included, and no live prices are looked up.
- No statutory tax rate, fee rate or market figure is ever guessed or applied automatically.
- Results are informational estimates based only on the values you enter.
- They do not guarantee any return and are not investment, legal or tax advice. No specific product is recommended.
- Intermediate values are not rounded; only the numbers on screen are rounded for display.
- Results may differ from other services, because what counts as a cost can be defined differently.
- Your inputs are calculated only in this browser and are never sent to or stored on a server.
Frequently asked questions
How do you calculate ROI?
Take the amount returned, subtract the investment cost to get the net profit, divide that net profit by the investment cost, then multiply by 100. For example, putting in 1,000 and getting back 1,200 leaves a net profit of 200, and 200 divided by 1,000 is 0.2, so the ROI is 20%.
What is a break-even return?
It is the amount you would have to get back to end up exactly where you started, which is always equal to the investment cost. At that point the net profit is 0 and the ROI is 0%. Getting back more than that is a gain, getting back less is a loss.
Does ROI take the investment period into account?
No. The formula has no place for a period, so 20% earned in one month and 20% earned over ten years both show as 20%. To compare investments that ran for different lengths of time you need an annualized return or CAGR, which this site provides on separate pages.
Is ROI the same as IRR or XIRR?
No. IRR and XIRR take every cash flow and the date it happened into account, while ROI only compares one total cost with one total result. When money went in and out at several different times those measures give different answers, and this calculator does not provide them.
Why can an investment cost of 0 not produce an ROI?
ROI is net profit divided by investment cost, and a cost of 0 leaves nothing to divide by. Forcing a number such as 0% or infinity would be misleading, so the calculator leaves the rate uncalculated and still shows the net profit and the amount returned.
How do I enter a loss?
Choose Use net profit and write the loss with a minus sign in front, such as -400. You can also stay on Use amount returned and enter a figure smaller than the investment cost. A loss larger than the investment cost is refused, because an amount returned below 0 has no meaning in this calculation.
Are taxes and fees included?
No. This calculator holds no tax rate or fee rate and never guesses one. If you want an after-tax figure, subtract the taxes and fees yourself and enter the reduced number. Inflation, exchange rates and market data are not included either, and no currency conversion happens anywhere on this page.
Does a past ROI predict future returns?
No. ROI describes a result that has already happened. It says nothing about what comes next and guarantees no return. Treat it as one way of summarising a past result, not as a forecast, and remember the answer is an informational estimate based only on the values you entered.
Are my inputs stored?
No. The calculation runs entirely in your browser, and your inputs are never sent to or stored on a server.
Related calculators
ROI stops at “how much came back compared with what went in”. The Investment Return Calculator takes the same idea and adds a period and any extra money you put in, so it can also show a simplified annualized return.
If you only know a beginning value, an ending value and how long they are apart, the CAGR Calculator smooths that whole change into one equivalent annual rate. To look forward instead of back, the Compound Interest Calculator takes a principal, an expected annual return and a period. It is a hypothetical simulation and guarantees no return.