What ROI does and does not tell you
ROI is a single percentage that compares what you got back to what you put in — simple to compute and easy to compare across very different investments. What it does not capture on its own is time: a 30% return earned in 3 months is a very different outcome from the same 30% earned over 5 years.
Why annualized ROI matters
Annualized ROI (using the CAGR formula) normalizes your return to a per-year basis, so investments held for different lengths of time can be fairly compared. Switch to Annualized mode and enter how long you held the investment to see this figure, plus which of three broad performance bands — Conservative, Target, or High Growth — it falls into.
Reading the investment-scaling chart
The chart shows how return and profit would scale if you had invested more or less at this same return rate. Because profit and investment size are proportional at a fixed rate, this scenario is either profitable at every investment level or unprofitable at every level — there is no single "break-even investment size" to look for.
What this calculator does not cover
This models invested vs. returned amounts only — it does not account for taxes, transaction fees, inflation, or risk-adjusted required rates of return. For ad-spend-specific efficiency, see the ROAS Calculator; for a customer-value view over time, see the CLV Calculator.