Return on investment, or ROI, is the universal yardstick for whether money was well spent. It expresses your gain as a percentage of what you put in, making very different investments comparable on one scale. The ROI Calculator computes both the headline ROI and the annualized rate, so you can judge not just how much you earned but how fast.
How ROI is calculated
Basic ROI is your net gain divided by the amount invested. The net gain is the total return minus what you invested. Multiplying by 100 turns it into a percentage. A positive ROI means a profit; a negative ROI means a loss.
ROI % = (return - invested) / invested * 100 annualized % = ((return / invested) ^ (1 / years) - 1) * 100
Why annualized ROI matters
A 50 percent ROI sounds great, but over how long? Earning 50 percent in one year is excellent; earning it over ten years is modest. Annualized ROI fixes this by expressing the return as an equivalent yearly rate, accounting for compounding over the holding period. It lets you compare a quick flip against a long hold fairly.
Calculating return on investment
- Enter the amount invested, your total cost or capital in.
- Enter the return, the total amount you received or the current value.
- Enter the holding period in years to unlock the annualized rate.
- Read both the simple ROI and the annualized ROI.
A worked example
Suppose you invest 1,000 and it grows to 1,500 over 3 years. The simple ROI is (1500 - 1000) / 1000 * 100 = 50 percent. The annualized rate is ((1500 / 1000) ^ (1 / 3) - 1) * 100, which works out to about 14.5 percent per year. So a 50 percent total return is roughly 14.5 percent compounded annually, a much fairer figure for comparison.
Comparing opportunities
Use simple ROI for a quick verdict and annualized ROI to compare investments held for different lengths of time. The calculator handles both and runs entirely in your browser, so your investment figures remain private to you.
ROI vs payback — two numbers, two questions
ROI answers “how much did it return”; payback period answers “how fast do I get my money back”. Two projects can share an ROI while one pays back in 4 months and the other in 4 years — and for cash-strapped teams the payback period decides. Annualizing also matters: a 30% ROI earned in a quarter is worth more than the same ROI earned in three years. Compare like-for-like on time, then rank by the metric the stage of the business actually needs.
- Use ROI to compare efficiency between opportunities.
- Use payback to judge whether you can afford the wait.
- Recompute the annualized number when the timeline is not one year.
