How does the ROI Calculator work?
ROI = (proceeds − investment) ÷ investment × 100. A 30 % ROI means 100 turned into 130.
Background & details
How to read your result
ROI tells you in a single number what percentage of your invested capital came back as profit. An ROI of 0 % means you got exactly your stake back – no gain, no loss. A negative ROI means a loss: at −25 %, 100 turned into just 75. The net profit shown in currency helps you judge whether a high percentage actually matters in absolute terms – a 200 % ROI on €50 is only €100 of profit.
Typical values in context
- Safe assets (savings, bonds): 2–4 % per year.
- Broad stock market (index ETF): historically 7–10 % per year.
- Real estate: often 3–6 % rental yield plus appreciation.
- Start-ups and one-off ventures: high risk, so aim for 20 %+ to offset failures.
Common mistakes
The biggest mistake is ignoring the time factor. A 50 % ROI in one month is excellent; the same 50 % over ten years is poor. For a fair comparison you need the annualised return – use the compound interest calculator for that. Second mistake: forgetting side costs. Fees, taxes, transaction costs and your own time all eat into the real ROI. Always calculate with the actual net proceeds, not the gross return.
Practical tips
Always compare investments of similar risk and similar duration – only then is ROI meaningful. Set a minimum ROI that a project must beat to be worth it versus a simple ETF. For bigger decisions, stress-test a pessimistic scenario: what is the ROI if proceeds come in 20 % lower than hoped? That habit prevents nasty surprises.
When ROI is the wrong measure
For ongoing investments spanning several years, for cash flows arriving at different times, or for projects with staggered payouts, plain ROI is too crude. In those cases, internal rate of return (IRR) or net present value (NPV) are the better tools.
ROI in marketing and business
In marketing, ROI is often expressed as ROAS (return on ad spend): how much revenue does each euro of ad budget generate? Watch the difference between revenue and profit here – a 4:1 ROAS sounds strong, but on a thin margin it may barely cover costs. In a business context it also pays to calculate ROI not only for whole projects but for individual levers: which channel, which campaign, which product returns the most per euro spent? That way capital flows to where it works hardest.