ROI Calculator

Before you calculate

Use this calculator when the question is a simple before-and-after return: how much value changed, what that change means as a percentage of the starting amount, and how the same result looks on an annualized basis. Use the average return calculator when several periods or cash flows matter, the IRR calculator for dated deposits and withdrawals, the investment calculator for ongoing contributions, and the payback period calculator when recovery time is the main question.

Formula summary

The calculator subtracts Amount invested from Amount returned to get signed gain or loss. ROI is that gain divided by Amount invested and multiplied by 100, with a zero-investment guard that returns 0 percent instead of dividing by zero. Length mode uses the entered Investment length in years and rounds years * 365 for holding days. Date mode counts elapsed UTC calendar days and divides by 365. Annualized ROI is ((Amount returned / Amount invested)^(1 / holding years) - 1) * 100 when invested amount, returned amount, and holding years are all positive; otherwise the annualized output is 0.

Worked example

Example: $1,000 returned as $2,000 over 4.614 years

With the default inputs, $1,000 invested, $2,000 returned, Length mode, and 4.614 years produce a $1,000 investment gain, 100.00 percent ROI, 16.21 percent annualized ROI, 4.61 holding years, and 1,684 holding days. A date-mode example with $5,000 invested, $6,500 returned, 15 June 2021 to 15 June 2024 produces a $1,500 gain, 30.00 percent ROI, about 9.13 percent annualized ROI, 3.00 holding years, and 1,096 days. A loss example with $10,000 invested, $8,500 returned, and 2 years produces a -$1,500 gain, -15.00 percent ROI, and -7.80 percent annualized ROI.

The result explains one simple start-to-end return from the inputs. It is not a prediction, tax calculation, fee analysis, risk assessment, performance report, product comparison, or recommendation to buy, sell, hold, or choose an investment.

Assumptions

• Amount invested, Amount returned, and the selected holding-period input describe the whole start-to-end scenario. The calculator does not know about interim deposits, withdrawals, dividends, income, fees, expenses, taxes, or reinvestment timing unless they are already reflected in Amount returned.
• Date mode uses elapsed UTC days divided by 365. It does not use trading days, provider performance conventions, actual/actual day counts, benchmark returns, volatility, risk measures, or professional performance-reporting rules.
• Results use the numbers entered on the page, round currency and percent outputs to two decimals, and are educational estimates rather than financial, tax, legal, lending, investment, provider, or regulated advice.

Common mistakes to avoid

• Comparing total ROI across different holding periods without checking annualized ROI. A large total return over many years may be less comparable than a smaller return over a short period.
• Treating Amount returned as automatically net of fees, taxes, dividends, income, or sale costs. Enter the returned amount after those items only when you want them reflected in the estimate.
• Using this simple ROI model when cash-flow timing matters. If there were deposits, withdrawals, or irregular cash flows during the holding period, average return or IRR may be a better calculator match.

Methodology and sources

This calculator is an original implementation based on documented formulas, app-specific assumptions, deterministic fixtures, edge cases, rounding policy tests, and internal validation. It is not copied from a single source.

Outputs are checked with deterministic fixtures, edge cases, rounding policy tests, and internal independent comparator checks where overlapping outputs are available. The result remains an educational estimate, not a quote, approval, tax answer, or personalised advice.

Formula version 2026.05.22-generic-roi. The version marks the calculation logic and validation fixture set used for this estimate.

• Investor.gov Investment Products, What is Risk, and Understanding Fees materials should be used before copy discusses investment-product features, risk, return, diversification, liquidity, fees, costs, fraud, or real-world return interpretation.
• IRS Topic 409 and relevant tax-authority materials should be used before copy discusses US capital gains, capital losses, holding-period tax classification, reporting, loss deductibility, estimated tax, or net investment income tax.
• SEC, FINRA, FCA, MoneyHelper, product documents, prospectuses, fee disclosures, brokerage statements, provider materials, and relevant local regulators should be used before copy frames simple ROI as regulated performance reporting, time-weighted return, money-weighted return, product-specific returns, benchmark comparisons, legal claims, or jurisdiction-specific guidance.

Estimate only

The result is educational and is not financial, tax, legal, lending, investment, or regulated advice. Real provider terms, fees, rates, taxes, and personal circumstances can change the final answer.

Formula and help: read the full roi calculator methodology notes.

Related reading

• How Calcs.finance validates calculator formulas
• Estimate limitations and not-advice disclaimer

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