The ROI Calculator reduces any finished or proposed investment to its essential figures: net profit, total ROI percentage, the return multiple, and — when you add the holding period — the annualized return (CAGR) that makes different investments comparable. Three inputs: what went in, what came out, and optionally over how long.
How It Works
The return multiple (returned ÷ invested) is the same information in ratio form: 1.64× means every dollar became $1.64. Results are reported to four decimal places, and the annualized figure is the compound rate that would produce the same endpoints if growth had been perfectly smooth.
Worked Example 1: A Gain
Invest 41,000 back after 5 years: net profit $16,000, total ROI 64%, multiple 1.64×, annualized ROI 10.3999%. Note the difference between 64 ÷ 5 = 12.8% (simple division) and the true 10.40%: compounding means the smoothed annual rate is always lower than the naive average, because each year's growth builds on a bigger base.
Worked Example 2: A Loss
Invest 9,600 after 2 years: net profit **−0 → ROI −100%, multiple 0).
What ROI Does Not Measure
Time, unless you supply it: a 64% ROI over 5 years (10.40% annualized) and over 15 years (3.36%) are different investments wearing the same headline — always enter the length. Risk: ROI is silent on volatility and the chance of loss; a speculative 30% and a guaranteed 30% score identically here and nowhere else. Cash-flow timing: the formula assumes one amount in at the start and one amount out at the end. Investments with money moving in between — staged funding, interim dividends you spend, additional purchases — need an internal-rate-of-return treatment; fold interim cash you kept into "amount returned" for a fair approximation. Inflation: returns are nominal; at 3% inflation, a 10.40% annualized return is roughly a 7.2% real one.
For marketing and business spending the same discipline applies: "returned" must mean incremental profit attributable to the spend, not revenue it touched — the most common ROI inflation in practice. When the amount returned is genuinely revenue, divide by the margin first.
Limitations
The calculator needs a positive amount invested (division by zero is rejected), a non-negative amount returned, and a positive period for annualization. It does not model fees, taxes, or currency effects — net them into the returned figure before entering. Annualized ROI assumes smooth compounding between the two endpoints; it describes the journey's average steepness, not the journey.
Frequently Asked Questions
What is a good ROI?
Context decides. Broad stock markets have historically delivered roughly 7 to 10% annualized over long periods; a business project is usually judged against its cost of capital plus a risk premium; a savings account's 4% is "good" for zero risk. The annualized figure in this calculator is what makes the comparison against those yardsticks honest.
Why is annualized ROI lower than total ROI divided by years?
Because of compounding. Growing at 10.40% for five years multiplies money by 1.104⁵ ≈ 1.64 — the same endpoint as a single 64% jump. Dividing 64 by 5 pretends the growth was linear, crediting each year with growth on the original principal only, and overstates the yearly rate whenever returns are positive.
Can ROI exceed 100%?
Yes, without limit — a multiple above 2× is an ROI above 100%. What ROI cannot do is fall below −100%: you cannot lose more than everything in a simple long investment, which is why the loss example's −20% and even a total wipeout (−100%) sit on a bounded scale while gains do not.