Calculate return on investment, net profit, annualised ROI, and payback period — with scenario comparison and a break-even table.
How a 20% variance in return changes the picture
This ROI calculator turns an investment and its expected return into the numbers that actually matter — return on investment as a percentage, net profit in dollars, annualised ROI, and how long it takes to pay back the money you put in. It also runs a conservative/optimistic scenario comparison and, when you add ongoing monthly costs, builds a month-by-month break-even table.
Return on investment is the single clearest way to judge whether the money you commit earns its keep, but raw ROI can mislead across different time horizons — a 30% return over three years is weaker than 30% in one year. By computing annualised ROI and payback alongside the headline figure, this tool keeps the comparison honest. People use it to:
Everything runs local and in-browser — your numbers never leave your device, nothing is stored or sent to a server, and the calculation updates instantly as you type.
ROI equals net profit divided by the initial investment, expressed as a percentage. This tool computes net profit as total return minus total cost, where total cost is the initial investment plus any monthly costs over the time horizon, then divides that profit by the initial investment.
Annualised ROI converts a total return into an equivalent 12-month rate so investments of different lengths can be compared fairly. It is calculated as (1 + ROI)^(12 / months) − 1. A 30% return over 36 months annualises to roughly 9.1% per year, which is far weaker than 30% earned in a single year.
The payback period is how long it takes to recover the initial investment from the project's average monthly net cash flow. The break-even point is the month where cumulative revenue first overtakes cumulative cost — shown with a ✓ in the break-even table once you enter monthly costs.
Profit is an absolute dollar amount — what you earned after costs. ROI is a ratio that expresses that profit relative to the capital deployed. A $5,000 profit looks great on a $10,000 investment (50% ROI) but mediocre on a $500,000 investment (1% ROI), which is why ROI is the better comparison tool.
For passive investments, 7–10% per year is solid. For active business projects, 20%+ is a healthy benchmark. Always compare against your cost of capital — an 8% ROI when your loan rate is 8% is merely breaking even.
ROI compares profit to the capital deployed; profit margin compares profit to revenue. A capital-light business can show high margins with modest ROI, or the reverse. They answer different questions, so it is worth checking both.
No. The figures are nominal. For long horizons, subtract the inflation rate from the annualised ROI to estimate a real return, or use NPV and IRR analysis for fully time-value adjusted comparisons.