ROI (Return on Investment) measures how much money an investment made or lost relative to the amount put in. A 40%% ROI on $10,000 over 4 years is excellent — but if you measure it per year, it's only ~8.7%% annualized. The ROI calculator below shows both metrics, with the annualized version (CAGR) being the comparison standard across investments of different durations.

What is ROI?

ROI (Return on Investment) is a basic performance metric used in business, finance, and marketing. The basic formula is the same everywhere:

ROI %% = (Net Profit / Cost of Investment) × 100

Where Net Profit = Final Value − Initial Investment − Additional Costs.

A $10,000 investment that grew to $14,000 with $250 in fees has:

• Net Profit = 14,000 − 10,000 − 250 = $3,750
• ROI %% = (3,750 / 10,250) × 100 = 36.59%%

Why Annualized ROI (CAGR) Matters

If a real-estate deal returned 36.59%% over 4 years, that's a great result. But is it better or worse than a savings account that returned 4%% per year for the same period?

The 4-year savings account returned (1.04^4) − 1 = 16.99%% total — less than half the real-estate deal's total return.

But comparing the 36.59%% number to a savings account's 4%% annual number is apples-to-oranges. To compare them on equal footing, you annualize:

CAGR = ((1 + ROI_total)^(1/years)) − 1 = ((1.3659)^(1/4)) − 1 = 8.10%% per year

So the real-estate deal annualized to 8.10%% per year — roughly 2x the savings account. That's the right comparison.

Why CAGR is Better than Average Annual Return

Many people use "average annual return" to compare investments, but it produces misleading numbers for volatile investments. If an investment returns −50%% in year 1 and +200%% in year 2, the average is +75%% per year — but the actual CAGR is only +41.4%% per year. CAGR is the geometric mean and the correct comparison metric.

ROI Formulas by Use Case

Marketing ROI (Marketing Return on Ad Spend)

Marketing ROI %% = ((Revenue − Ad Spend) / Ad Spend) × 100

A marketing campaign that cost $10,000 and generated $35,000 in attributed revenue has Marketing ROI = 250%%. Note: This is gross ROI. Net-of-cost ROI subtracts COGS, fulfillment, and overhead.

Real-Estate ROI (Cash-on-Cash Return)

Cash-on-Cash %% = (Annual Cash Flow / Cash Invested) × 100

A rental property that costs $50,000 down and produces $6,000/year in cash flow has CoC = 12%%. This differs from total ROI because it ignores appreciation and principal paydown.

Stock ROI (with Dividends Reinvested)

For investment portfolios, ROI often incorporates dividends, capital gains, and time. The total-return formula is:

Total Return %% = ((Final Value + Distributions) / Initial Value − 1) × 100

Business Investment ROI (NPV-IRR)

For business projects, ROI is often calculated with NPV (Net Present Value) and IRR (Internal Rate of Return) which incorporate the time value of money. The simple ROI above does not.

How to Use the ROI Calculator

Step 1: Enter initial investment. The amount you put in initially.

Step 2: Enter final value. What the investment is worth now (or at the end of the holding period).

Step 3: Enter additional costs (optional). Management fees, transaction costs, commissions, taxes paid during the period. The calculator subtracts these from your profit.

Step 4: Enter holding period in years (optional). If provided, the calculator also shows CAGR (annualized return). If omitted, only total ROI is shown.

Step 5: Click Calculate ROI. The result card shows total ROI, net profit, total invested, and CAGR.

Real-World Examples

Example 1: Stock portfolio

• Initial: $50,000 invested in VTI (Vanguard Total Stock Market)
• Final: $72,000 after 4 years
• Costs: $200 in fees
• Years: 4
• ROI: 43.65%% (total), CAGR: 9.53%%/yr

Example 2: Rental property

• Initial down payment: $80,000
• Final value (5 years later): $120,000
• Additional costs (repairs, closing): $8,000
• Years: 5
• ROI: 37.50%% (total), CAGR: 6.57%%/yr
• Note: This excludes cash flow during the 5 years.

Example 3: Marketing campaign

• Ad spend: $10,000
• Revenue attributed: $42,000
• Costs: $0
• Years: 0.25 (3-month campaign)
• ROI: 320.00%% (3 months), annualized: annualized ROI is not meaningful for short campaigns

Example 4: Side hustle investment

• Initial: $3,000 (equipment)
• Final value of equipment: $500
• Revenue generated: $8,500 over 2 years
• Total return (revenue + final): $9,000
• Costs: $1,500 (maintenance, supplies)
• Years: 2
• ROI: 137.50%% (total), CAGR: 53.69%%/yr

Example 5: Negative-ROI learning experience

• Initial: $10,000
• Final: $7,000
• Costs: $500
• Years: 2
• ROI: −35.00%% (total loss), CAGR: −19.66%%/yr — the calculator renders negative numbers in red.

Limitations of Simple ROI

Doesn't account for time. A 100%% ROI in 6 months is twice as good as a 100%% ROI in a year. Use CAGR.

Doesn't account for risk. A 30%% expected ROI on a 50/50 gamble might have a 15%% CAGR but it's much riskier than 15%% CAGR in a CD.

Doesn't account for cash-flow timing. A real-estate deal that returns 50%% over 5 years with all the profit at year 5 is less valuable than one that returns 30%% over 5 years with cash flow along the way.

Sensitive to "additional costs" definition. Include or exclude closing costs, fees, taxes? Results differ by 5–10%. Be consistent across comparisons.

Doesn't handle multi-currency or multi-period comparisons well. For those, use IRR or NPV with explicit discounting.