How to Calculate Investment ROI: Complete Formula Guide + Examples

Introduction

You invested $10,000 in stock. After one year, it's worth $11,500. How much did you actually earn?

The answer isn't "$1,500." It's more nuanced—and understanding why matters if you're comparing investments, evaluating advisor performance, or tracking your wealth growth.

AEO Snippet: To calculate Investment ROI, use the formula: (Ending Value - Starting Value) / Starting Value x 100. For a more accurate picture of long-term performance, calculate the Annualized ROI using ((Ending Value / Starting Value)^(1/n) - 1) x 100, where 'n' is the number of years. In 2026, always ensure you subtract inflation and management fees from your gross ROI to find your "real" return.

Return on Investment (ROI) is the most fundamental metric in investing. Yet most people calculate it wrong, compare it unfairly, or misunderstand what it actually means.

This guide shows you exactly how to calculate ROI correctly, compare investments fairly, and identify when an investment is actually performing well.

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The Basic ROI Formula

``` ROI = (Ending Value - Starting Value) / Starting Value × 100% ```

Example:
  • •Starting value: $10,000
  • •Ending value: $11,500
  • •Gain: $1,500
  • •ROI: ($1,500 / $10,000) × 100% = 15% ROI
This means you earned a 15% return on your investment over the period measured.

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Step-by-Step Calculation

Step 1: Determine Your Starting Value

This is how much you invested initially.

Example: You buy 100 shares of XYZ stock at $100/share = $10,000 starting value

Step 2: Determine Your Ending Value

This is what your investment is worth now (or when you sold).

Example: You sell 100 shares of XYZ at $115/share = $11,500 ending value

Step 3: Calculate the Gain

``` Gain = Ending Value - Starting Value Gain = $11,500 - $10,000 = $1,500 ```

Step 4: Divide by Starting Value

``` ROI ratio = Gain / Starting Value ROI ratio = $1,500 / $10,000 = 0.15 ```

Step 5: Convert to Percentage

``` ROI % = ROI ratio × 100% ROI % = 0.15 × 100% = 15% ```

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Advanced: Annualized ROI (For Multi-Year Investments)

If your investment lasted more than one year, you should calculate annualized return.

Example:
  • •Starting: $10,000
  • •Ending (after 3 years): $13,500
  • •Total return: 35%
  • •But what's the annual return? Not 35% ÷ 3 = 11.7% (this is wrong)

Correct Formula: Annualized ROI

``` Annualized ROI = (Ending Value / Starting Value) ^ (1 / Years) - 1 × 100% ```

Calculation: ``` ($13,500 / $10,000) ^ (1/3) - 1 = 1.35 ^ 0.333 - 1 = 1.105 - 1 = 0.105 = 10.5% annualized ROI ``` Why this matters: Compound returns. A 10.5% annual return for 3 years = 35% total (due to compounding), not 31.5%.

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ROI With Dividends or Income

If your investment paid dividends, you must include them in ROI.

Example:
  • •Starting investment: $10,000
  • •Ending value: $11,500
  • •Dividends received (during holding period): $400
  • •Total gain: $1,500 + $400 = $1,900
  • •Total ROI: ($1,900 / $10,000) = 19%
This is critical for stocks, bonds, and REITs that pay dividends. Many investors forget to include the dividend income in their ROI calculation.

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ROI With Withdrawals or Additions

If you added or withdrew money during the investment period, use Money-Weighted Return (MWR):

Simplified approach:
  • •Add back any withdrawals
  • •Subtract any additions
  • •Calculate ROI on average balance
Example:
  • •Starting: $10,000
  • •Year 1: Earn $1,000 (now worth $11,000)
  • •Add: $5,000 (now worth $16,000)
  • •Year 2: Earn $2,000 (now worth $18,000)
Calculation: ``` Total gain: $18,000 - $10,000 - $5,000 = $3,000 Average invested capital: ~$13,000 (rough average) ROI: $3,000 / $13,000 = 23% ```

For precise calculation, use money-weighted return (covered in our advanced calculator).

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ROI vs. Other Return Metrics

ROI vs. Absolute Return

  • •ROI: Percentage return (15%)
  • •Absolute return: Dollar amount ($1,500)
Both are useful. ROI is better for comparing investments of different sizes.

ROI vs. Total Return

  • •ROI: Gain on original investment (works well for one-time investments)
  • •Total return: Includes all gains + dividends + interest (better for portfolios)

ROI vs. Annualized Return

  • •ROI: Total return over the period (useful for comparing to benchmarks)
  • •Annualized return: Average annual return (better for multi-year comparisons)

ROI vs. Internal Rate of Return (IRR)

  • •ROI: Simple percentage gain ((End - Start) / Start)
  • •IRR: Compound annual return accounting for timing of cash flows (more accurate for real-world scenarios)
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Real-World ROI Examples

Example 1: Stock Investment

Scenario:
  • •Buy 50 shares of ACME at $100 = $5,000
  • •Stock rises to $130 = $6,500
  • •Receive $50 in dividends
Calculation: ``` Gain: $6,500 - $5,000 + $50 = $1,550 ROI: $1,550 / $5,000 = 31% ```

Example 2: Real Estate Rental Property

Scenario:
  • •Property purchase price: $300,000
  • •Property value after 5 years: $390,000
  • •Net rental income received (5 years): $25,000
  • •Closing costs/fees: $15,000
Calculation: ``` Gain: $390,000 - $300,000 + $25,000 - $15,000 = $100,000 ROI: $100,000 / $300,000 = 33.3% (5-year total) Annualized: 33.3% / 5 years = 6.67% annually (rough) More precise annualized: (390,000 / 300,000 + 25,000 ROI) ^ (1/5) - 1 = ~5.96% ```

Example 3: Bond Investment

Scenario:
  • •Buy bond for $10,000
  • •Hold 3 years, receive $750/year in interest = $2,250 total
  • •Bond matures at $10,000
Calculation: ``` Gain: $2,250 interest (principal unchanged) ROI: $2,250 / $10,000 = 22.5% (3-year total) Annualized: 22.5% / 3 = 7.5% annually ```

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Benchmark Comparison: Is Your ROI Good?

ROI only means something in context. A 15% return is excellent... if the market returned 5%. But it's terrible if the market returned 20%.

Benchmark Comparison Example

Your portfolio:
  • •$100,000 invested
  • •Returns 12% = $12,000 gain
  • •ROI: 12%
S&P 500 benchmark:
  • •Same period: 18% return
Comparison:
  • •Your ROI: 12%
  • •Benchmark: 18%
  • •Underperformance: 6 percentage points (this is a problem)

Common Benchmarks

Investment TypeBenchmark
US Large-cap stocksS&P 500 (average ~10% annually)
Diversified stock portfolioRussell 3000 or total market index
Bond portfolioBloomberg Aggregate Bond Index (~4-5% annually)
Real estateReal Estate Investment Trust (REIT) index
BusinessIndustry average ROI or cost of capital

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Time-Weighted vs. Money-Weighted ROI

Time-Weighted ROI (Better for Comparing Managers)

Removes the impact of your deposits/withdrawals to see how well the investment actually performed.

Example:
  • •You invested $10,000 in a fund
  • •Fund rose 20% = $12,000
  • •You added $5,000 (total now $17,000)
  • •Fund rose another 10% = $18,700
Time-weighted ROI:
  • •Period 1: 20%
  • •Period 2: 10%
  • •Average: 15% (ignoring the additional deposit)
This shows the investment's true performance regardless of your contribution timing.

Money-Weighted ROI (Better for Personal Performance)

Accounts for when you added/withdrew money.

Same example:
  • •Gain: $18,700 - $10,000 - $5,000 = $3,700
  • •Money-weighted ROI: ~18% (higher because you added money after gains)
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Common ROI Mistakes

Mistake 1: Forgetting Fees

Investment fees reduce your ROI significantly:

Example:
  • •Investment return: 10%
  • •Fees: 2%
  • •Actual ROI: 8% (the 10% minus fees)
Always calculate ROI net of fees.

Mistake 2: Ignoring Taxes

Capital gains taxes reduce after-tax ROI:

Example:
  • •Investment gain: $10,000 (20% ROI)
  • •Capital gains tax (15%): $1,500
  • •After-tax ROI: 17% (or less if state taxes apply)
For tax-deferred accounts (401k, IRA), taxes are postponed, so you don't adjust currently.

Mistake 3: Mixing Time Periods

Comparing 1-year ROI to 5-year ROI is misleading. Use annualized returns for comparison.

Mistake 4: Not Annualizing Multi-Year Returns

A 50% return over 5 years is not 10% annually (it's ~8.4%).

Mistake 5: Comparing Apples to Oranges

A 20% return on a risky stock can't be compared fairly to a 5% bond return without considering risk.

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Using Our ROI Calculator

Our ROI calculator instantly calculates:

  • 1.Basic ROI: Starting value, ending value, time period
  • 2.Annualized return: For multi-year investments
  • 3.With dividends/income: Include distributions
  • 4.With fees/taxes: Account for real costs
  • 5.Benchmark comparison: How you stacked up
  • 6.Portfolio analysis: ROI across multiple investments
Simply enter:
  • •Starting and ending values
  • •Time period
  • •Any additions/withdrawals
  • •Dividends or interest received
  • •Fees and taxes
The calculator shows your exact ROI, annualized return, and how it compares to market benchmarks.

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Key Takeaways

✓ ROI = (Ending Value - Starting Value) / Starting Value × 100% ✓ For multi-year investments, use annualized ROI ✓ Include dividends/interest in ROI calculation ✓ Account for fees and taxes in after-tax ROI ✓ Compare ROI to relevant benchmarks (not in a vacuum) ✓ Use time-weighted ROI to compare investment managers ✓ Use money-weighted ROI to assess your personal performance

Next Steps

  • 1.Calculate your investment ROI using our calculator
  • 2.Compare to benchmarks (S&P 500, bond index, etc.)
  • 3.Review our guide on portfolio performance optimization
  • 4.Explore Roth vs. Traditional accounts to optimize after-tax returns
Understanding your ROI is the foundation of intelligent investing. Calculate it correctly, compare it fairly, and use it to make better decisions.

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