ROI Calculator
Calculate return on investment as a percentage, plus profit and annualised return.
Results update as you type.
About this calculator
Return on investment (ROI) measures the gain or loss on an investment relative to what you put in, expressed as a percentage. This calculator shows the simple ROI, the raw profit in currency, and the annualised (compound) return so you can compare investments held for different lengths of time on an equal footing.
Simple ROI is (final value − amount invested) ÷ amount invested × 100. Turning 1,000 into 1,500 is a 500 profit, so ROI = 500 ÷ 1,000 = 50%. But a 50% gain earned over five years is not the same as 50% in one year, so the tool also computes the annualised return, ((final ÷ initial)^(1 ÷ years) − 1) × 100 — for this example about 8.45% a year, the rate that compounds 1,000 up to 1,500 over five years.
Use ROI to judge whether an investment, project or marketing spend paid off, and use the annualised figure whenever you compare options held for different periods or against a benchmark quoted per year. Note that simple ROI ignores the timing of cash flows and any ongoing costs, so pair it with the annualised return for a fair picture.
Frequently asked questions
How is ROI calculated?
ROI = (final value − amount invested) ÷ amount invested × 100. Turning 1,000 into 1,500 is a gain of 500, so ROI = 500 ÷ 1,000 × 100 = 50%.
What is annualised return and why does it differ?
Annualised return spreads the total gain evenly across each year using compounding: ((final ÷ initial)^(1 ÷ years) − 1) × 100. A 50% total return over 5 years is only about 8.4% per year, which is the fairer number for comparing holdings of different lengths.
What is a good ROI?
It depends entirely on the risk and the time frame. Broad stock-market investments have historically returned roughly 7–10% a year before inflation, so an annualised return well above that usually means higher risk. Any positive ROI beats a loss, but compare it against what a safe alternative would earn.
Can ROI be negative?
Yes. If the final value is less than the amount invested, the profit is negative and ROI is below zero — a loss. Selling something worth 1,000 for 800 is a −200 profit and a −20% ROI.
Does ROI account for fees, taxes and inflation?
No. Basic ROI compares only the money in and the money out. For a true picture, subtract trading fees, taxes on the gain and the effect of inflation, all of which reduce your real return below the headline percentage.
What is the difference between ROI and annualised return?
ROI is the total percentage gain over the whole holding period, while annualised return spreads that gain evenly across each year using compounding. For holdings longer than a year the annualised figure is always lower and is the fairer number for comparisons.
API — use this calculator from code
Call this calculator as a free JSON endpoint — no key required. Send the field values below as query parameters or JSON. Read the full API docs →
Endpoint
GET https://calculator.free/api/v1/roi/curl
curl "https://calculator.free/api/v1/roi/?initial=1000&final=1500&years=1"JavaScript fetch()
const r = await fetch(
"https://calculator.free/api/v1/roi/?" + new URLSearchParams({
"initial": "1000",
"final": "1500",
"years": "1"
}));
const data = await r.json();
console.log(data.results);Results are estimates for general guidance only, not financial, medical or tax advice.