Free ROI Calculator with CAGR, S&P 500 Benchmark, and Real Returns After Inflation
Free ROI Calculator — With CAGR & Inflation Adjustment
Calculate your total ROI, annualized CAGR, inflation-adjusted real return, and see how your investment compares to the S&P 500. No signup required.
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What is ROI and how is it calculated?
ROI (Return on Investment) measures what you earned relative to what you put in: ROI = (Final Value − Initial Investment) / Initial Investment × 100. A $10,000 investment that becomes $18,500 has an ROI of 85%. This is the total return over the entire holding period — it says nothing about how long you held it.
To compare investments held for different lengths of time, use CAGR — the compound annual growth rate. The formula is CAGR = (Final/Initial)^(1/years) − 1. An 85% ROI over 5 years equals a CAGR of 13.1%; over 10 years it equals 6.3%. Same total return, very different annualized performance.
What is a good ROI? The S&P 500 benchmark
The S&P 500 has returned approximately 10% per year (nominal) over the long term — roughly 7% after inflation. This is the standard benchmark for equity investors. Any investment with a CAGR above 10% outperformed a passive index fund strategy; below 10% means you would have done better in an index fund.
| $10,000 invested | 5 years | 10 years | 20 years | 30 years |
|---|---|---|---|---|
| At 6% CAGR | $13,382 | $17,908 | $32,071 | $57,435 |
| At 8% CAGR | $14,693 | $21,589 | $46,610 | $100,627 |
| At 10% CAGR (S&P 500) | $16,105 | $25,937 | $67,275 | $174,494 |
| At 12% CAGR | $17,623 | $31,058 | $96,463 | $299,600 |
How much do management fees cost you?
A 1% annual fee seems small but compounds aggressively. On $10,000 at 8% nominal for 20 years: with 0% fees → $46,610. With 1% fees → $38,697. The fee drag is $7,913 — the fees consumed 17% of your potential return. Over 30 years the drag is even larger. Passive index funds (0.03–0.10% expense ratios) versus actively managed funds (0.5–1.5%) represents a real performance difference that compounds for decades.
Nominal vs real returns: what inflation takes from you
A 10% nominal return with 3% inflation yields a real return of about 6.8% (exact: 1.10/1.03 − 1 = 6.8%). Over 20 years, this means your $67,275 nominal final value is worth only $37,243 in today's purchasing power. The inflation toggle on this calculator shows exactly what inflation takes from any investment scenario.
Frequently asked questions
ROI, CAGR, benchmarks, and real returns explained.
Investment return terms explained
- ROI (Return on Investment)
- Total percentage gain or loss on an investment relative to its original cost, over the entire holding period.
- CAGR
- Compound Annual Growth Rate — the constant annual rate that explains an investment's growth from start to end, accounting for compounding. The standard metric to compare investments.
- Annualized ROI
- Total ROI divided by the number of years held. A simpler approximation that does not account for compounding — less accurate than CAGR for multi-year returns.
- Nominal Return
- The raw percentage gain before adjusting for inflation. Reported by most brokerages and financial statements.
- Real Return
- Return after removing the effects of inflation, showing true growth in purchasing power. Real return ≈ nominal return − inflation rate.
- Fee Drag
- The cumulative reduction in final value caused by annual management fees. A 1% fee on a 20-year investment can reduce the ending balance by 15–20% due to compounding.
- Benchmark
- A reference index used to evaluate investment performance. The S&P 500 at ~10% annual return is the most common equity benchmark.
- Opportunity Cost
- The return foregone by choosing one investment over another. If you earned 6% CAGR while the S&P 500 earned 10%, your opportunity cost is ~4% per year.