Return on Investment (ROI) Calculator

What does return on investment measure?

A return on investment calculator divides the net gain from an investment, project or campaign by what it cost and shows the result as a percentage, then converts it to an annualised rate so periods of different length compare fairly, and, for marketing, measures the gain as gross profit rather than revenue.

Return on investment is the net gain from a project or asset divided by what it cost, shown as a percentage. If you spend $10,000 and get $12,500 back, the net gain is $2,500 and the ROI is 25.00%. The ratio answers one question: for every dollar put in, how many dollars of profit came out. A negative ROI means you got back less than you spent, and an ROI of exactly 0% means you broke even.

Because it is a ratio, ROI lets you compare a $500 purchase with a $50,000 one on the same footing. It does not tell you how large the gain was in dollars, how long it took, or how risky the outcome was. Those are separate questions, and the sections below say where to look for each.

Which costs belong in an ROI calculation?

The denominator should hold every cost the return depended on, not only the purchase price. That means the one-off amount, plus anything you had to keep paying: maintenance, subscriptions, staff time, platform fees. This calculator takes the one-off amount and a yearly ongoing cost, and multiplies the second by the period.

A project that costs $8,000 up front and $1,000 a year for three years has a total cost of $11,000, and returning $15,000 gives an ROI of 36.36%, not the 87.50% you would get by ignoring the running costs.

On the return side, count what you actually received and keep the original amount in it. If you enter only the profit as the return, the ratio comes out too low by exactly one hundred percentage points.

What is annualised ROI, and why does the holding period matter?

A 25% ROI over three years and a 25% ROI over one year are very different results, and plain ROI cannot tell them apart. Annualised ROI fixes this by finding the compound yearly rate that would grow the cost into the return over the same period. For 25% over three years that is 7.72% a year.

The formula is (1 + ROI) raised to the power of 1 divided by the years, minus 1: 1.25^(1/3) − 1 = 0.0772.

The result is a compound rate, not a simple average of ROI divided by years. It assumes the gain arrives as a single lump at the end and that the whole amount is invested for the whole period. Where money goes in or out at several points in time, an internal rate of return or net present value is the better tool, and the payback period answers a different question again: how long until the cost is recovered.

How is marketing ROI different from ROAS?

Marketing teams usually report ROAS, return on ad spend, which is revenue divided by ad spend. A ROAS of 5.00 means $5 of revenue for every $1 spent. It is not ROI, because revenue is not profit. The margin-adjusted form of ROI replaces revenue with gross profit: revenue times gross margin, less the spend, divided by the spend.

With $10,000 of revenue at a 40% margin and $2,000 of spend, gross profit is $4,000 and ROI is 100%, even though the ROAS is 5.00.

This also gives a break-even ROAS, which is 1 divided by the margin. At a 40% margin it is 2.50, so any campaign returning less than $2.50 of revenue per $1 of spend loses money. Add agency fees, creative and tools to the cost side if you want the whole campaign, as the Advanced option does.

What can't ROI tell you?

ROI ignores timing, risk and the alternative use of the money. It also depends on how the figures were measured: a gain that is partly estimated, or revenue that would have arrived anyway, inflates the result. Tax and financing costs are left out here, so compare like with like before comparing two ROI figures.

There is no universal level at which an ROI is good or bad; it depends on the period, the risk taken and what else the money could have done.