Head-to-head
ROI vs CAGR
ROI answers one question: how much did I make relative to what I put in? It is a single number for the whole holding period, with no reference to how long that period was. A 100% return is a 100% return whether it took two years or twenty.
CAGR answers a different question: what constant annual rate would have produced this ending value? It converts the total return into a rate you can compare against a savings account, an index fund or another investment with a different holding period. It is a smoothed rate — the actual path may have gone up 80% then down 10% — but the endpoint is exact.
The two are easy to confuse because they are often reported side by side without units. Dividing a 100% return by five years to get 20% a year is the standard mistake: it is simple division, not compounding, and it overstates the annual growth. The rate that actually reproduces the result is 14.87%, and the difference compounds into a very large gap over long periods.
A useful rule of thumb for spotting the error: if a quoted annual rate, compounded over the stated period, does not reproduce the stated final value, it is an average rather than a CAGR. Running that one check catches most of the misleading performance figures in circulation.
ROI
How To Calculate ROI
Return on investment expresses what you gained as a percentage of what it cost you. That single normalization is why ROI survives every criticism leveled at it: it works on a stock, a rental property, or a training program with exactly the same arithmetic.
CAGR
How To Calculate CAGR
CAGR compresses a messy multi-year history into one smooth annual rate. Because it reports the same kind of number for a seven-year stock hold and a five-year revenue line, it is the standard way to put two very different histories on one scale.
How They Differ
| Attribute | ROI | CAGR |
|---|---|---|
| What it measures | Total gain relative to the amount invested | The compound annual rate that reaches the same endpoint |
| Formula | (Final − Initial) ÷ Initial | (Final ÷ Initial)^(1 ÷ years) − 1 |
| Time in the calculation | Not included | The whole point of it |
| Units | Percent of the original investment | Percent per year |
| Comparable across different holding periods | No | Yes |
| Can be negative | Yes, down to −100% | Yes, but never below −100% |
| Best used for | Judging whether a single deal was worth doing | Comparing investments held for different lengths of time |
The Same Numbers, Both Ways
$10,000 invested, worth $20,000 after 5 years.
- Initial value
- $10,000
- Final value
- $20,000
- Holding period
- 5 years
| Line | ROI | CAGR |
|---|---|---|
| Money multiple | 2× | 2× |
| Total return | 100.0% | 100.0% |
| Reported as an annual rate | 20.0% (100.0% ÷ 5) | 14.87% |
| Value of $10,000.00 after 5 years at that rate | $24,883.20 | $20,000.00 |
Dividing the return by the holding period gives 20.0% a year, but 20.0% compounded for 5 years would turn $10,000.00 into $24,883.20 — $4,883.20 too much. The rate that actually reproduces $20,000.00 is 14.87%, which is what CAGR reports.
When To Use Each
ROI
- You want a quick verdict on a single deal: did this make money, and how much relative to the capital committed?
- The holding period is short or fixed, so there is nothing to normalise.
- You are comparing two investments held for exactly the same length of time.
CAGR
- You are comparing investments held for different periods — a 3-year fund against a 10-year fund.
- You want to check whether a return beat inflation or a benchmark over the long run.
- You are projecting forward: a CAGR is a rate you can compound, an ROI is not.
Common Questions
Is CAGR the same as average annual return?
No. The arithmetic average of yearly returns ignores compounding and will always be higher than CAGR when returns vary. A fund that goes +50%, −50%, +50% has an average of +16.7% a year but a CAGR of about 4%.
Why can I not just divide ROI by the number of years?
Because returns compound. Dividing assumes the gain arrives in equal linear slices, which overstates the annual rate whenever the total is positive. The error grows with both the return and the term.
Can CAGR be calculated for a loss?
Yes, and it will be negative. Going from $10,000 to $5,000 in five years is a CAGR of about −12.9% a year. It can never be below −100%, because an investment cannot lose more than everything.
Which one should appear in a pitch deck?
Both, with the period stated. ROI shows the size of the win; CAGR shows the rate. Quoting a CAGR without the period, or an ROI without the term, is how the same performance gets described as 20% and 14.87% in two different documents.
Does CAGR account for money added along the way?
No. CAGR assumes a single lump sum held throughout. If you added or withdrew money, the correct measure is a money-weighted return such as IRR, because your capital base changed.
More Comparisons
- Simple Interest vs Compound Interest
Simple interest charges the principal only; compound interest charges the balance. On $10,000 at 5% over 10 years that gap is $1,288.95 — here is where it comes from.
- APR vs APY
APR is the nominal annual rate; APY includes compounding. At 6% compounded monthly the gap is 0.17 points — $16.78 a year on $10,000, and $488 over five years.
- Markup vs Margin
Markup divides profit by cost; margin divides it by price. The same $20 profit is 50% markup and 33.3% margin — and the gap widens as the rate rises.
Sources
- Return on Investment (ROI) — investor glossary — U.S. Securities and Exchange Commission, Investor.gov
- Mutual fund performance — average annual total return — U.S. Securities and Exchange Commission
- Comparing investment performance over different periods — Financial Industry Regulatory Authority
Both methods sit in Finance.