How to Calculate ROI: Return on Investment Formula and Examples

What Is ROI and Why Does It Matter?

ROI measures the efficiency of an investment by comparing the net gain to the original cost. It answers a simple question: "For every dollar I put in, how many dollars did I get back?" The result is expressed as a percentage, which makes it easy to compare completely different investments on equal footing.

If you earned $2,000 on a $10,000 investment, your ROI is 20%. If someone else earned $5,000 on a $50,000 investment, their ROI is only 10%. Even though the second investor earned more in absolute dollars, your money worked harder on a percentage basis. That comparative power is what makes ROI so valuable for decision-making.

Businesses use ROI to decide which projects to fund. Marketers use it to justify ad spend. Individual investors use it to evaluate portfolio performance. It is universal, intuitive, and almost always the first metric people reach for when evaluating a financial decision.

The Basic ROI Formula

The simplest version of the ROI formula has just two components:

ROI = (Net Profit ÷ Cost of Investment) × 100

Where:

• Net Profit = Final Value of Investment − Cost of Investment
• Cost of Investment = The total amount you originally spent

You can also write this as:

ROI = ((Final Value − Initial Cost) ÷ Initial Cost) × 100

Both formulas produce the same result. Let us walk through a concrete example.

Example: Calculating Stock ROI

You purchased 100 shares of a company at $45 per share, spending $4,500 total. You also paid $10 in brokerage fees, making your total investment cost $4,510. Two years later, you sell all 100 shares at $62 per share, receiving $6,200. You pay another $10 selling fee, netting $6,190.

1. Calculate net profit: $6,190 − $4,510 = $1,680
2. Divide by cost: $1,680 ÷ $4,510 = 0.3726
3. Convert to percentage: 0.3726 × 100 = 37.26% ROI

This means you earned about 37 cents in profit for every dollar invested. Not bad — but remember, this return happened over two years, not one. That distinction matters, and it is why we need annualized ROI.

Simple ROI vs. Annualized ROI

The basic ROI formula tells you the total return regardless of time. If you earned 37.26% over two years, that is not the same as earning 37.26% per year. To compare investments held for different lengths of time, you need to annualize the return.

Annualized ROI = ((1 + ROI)^1/n − 1) × 100

Where n is the number of years the investment was held.

Example: Annualizing the Stock Return

Using our 37.26% total ROI over 2 years:

1. Convert ROI to decimal: 0.3726
2. Add 1: 1.3726
3. Raise to the power of 1/2: 1.3726^0.5 = 1.1717
4. Subtract 1: 0.1717
5. Multiply by 100: 17.17% annualized ROI

So while your total return was 37.26%, your equivalent annual return was 17.17%. This is significantly better than the S&P 500 average of roughly 10% per year, which gives you useful context for how your investment performed.

Why not just divide 37.26% by 2 to get 18.63%? Because that ignores compounding. Annualized ROI accounts for the fact that returns in year one generate their own returns in year two. The difference grows larger with longer holding periods.

ROI for Real Estate Investments

Real estate ROI is more complex than stock ROI because properties generate ongoing income, incur ongoing expenses, and appreciate in value over time. There are several ways to measure it.

Simple Real Estate ROI

Suppose you buy a rental property for $250,000, spend $30,000 on renovations, and pay $8,000 in closing costs. Your total investment is $288,000. After one year, the property generates $24,000 in rent and costs $10,000 in expenses (taxes, insurance, maintenance, management). Your net annual income is $14,000.

Cash-on-cash ROI = $14,000 ÷ $288,000 × 100 = 4.86%

Leveraged Real Estate ROI

Most investors do not pay all cash. If you put 20% down ($50,000) plus $30,000 renovation and $8,000 closing costs, your actual cash invested is $88,000. Your rental income is still $24,000, but you now have a mortgage payment. Assume $12,000 per year goes to mortgage interest and $10,000 to other expenses. Net cash flow is $2,000.

Cash-on-cash ROI = $2,000 ÷ $88,000 × 100 = 2.27%

That looks low, but it does not account for mortgage principal paydown (building equity) or appreciation. If the property appreciates 3% in year one ($7,500) and you paid $6,000 in principal, your total return including those factors is $2,000 + $7,500 + $6,000 = $15,500.

Total ROI = $15,500 ÷ $88,000 × 100 = 17.61%

Leverage amplifies returns when property values rise, but it also amplifies losses when they fall.

ROI for Marketing Campaigns

Marketing ROI, sometimes called ROAS (Return on Ad Spend), measures how much revenue a campaign generated relative to its cost.

Marketing ROI = (Revenue from Campaign − Cost of Campaign) ÷ Cost of Campaign × 100

Example: Google Ads Campaign

You spend $3,000 on Google Ads over one month. The campaign generates 150 leads, 30 of which become customers spending an average of $250 each. Total revenue is $7,500.

1. Net profit: $7,500 − $3,000 = $4,500
2. ROI: $4,500 ÷ $3,000 × 100 = 150% ROI

A 150% ROI means you earned $1.50 in profit for every dollar spent, or a 2.5:1 return ratio. In marketing, anything above 100% ROI (2:1 ratio) is generally considered good, while 400% (5:1) is considered excellent.

One important consideration: marketing ROI should account for all costs, including creative production, agency fees, software tools, and employee time — not just the ad spend itself.

ROI for Business Projects

When a company considers internal projects like upgrading software, expanding a warehouse, or launching a new product line, ROI helps prioritize limited budgets.

Example: Software Upgrade

A manufacturing company spends $120,000 on new inventory management software. Implementation, training, and migration cost another $30,000. The total investment is $150,000. The software reduces waste, speeds up fulfillment, and cuts labor hours, saving the company $55,000 per year.

Year 1 ROI: ($55,000 − $150,000) ÷ $150,000 × 100 = −63.3% (net loss)

Cumulative Year 3 ROI: ($165,000 − $150,000) ÷ $150,000 × 100 = 10%

Cumulative Year 5 ROI: ($275,000 − $150,000) ÷ $150,000 × 100 = 83.3%

The payback period is about 2.7 years. After that, the investment generates pure profit. This is a common pattern for capital expenditures and technology investments — negative ROI early on, with compounding returns over time.

Limitations of ROI

Despite its popularity, ROI has significant limitations that you should understand before relying on it exclusively.

Time Is Ignored

Basic ROI does not tell you how long it took to earn the return. A 50% ROI earned in one year is far better than a 50% ROI earned over ten years. Always calculate annualized ROI when comparing investments with different holding periods.

Risk Is Not Measured

Two investments might both offer a projected 15% ROI, but one could be a government bond and the other a speculative startup. ROI does not quantify the probability of actually achieving the return. Metrics like the Sharpe Ratio or standard deviation of returns capture risk more accurately.

Opportunity Cost Is Missing

If you earned a 7% ROI on a rental property, that sounds reasonable. But if the stock market returned 12% over the same period, your capital would have performed better elsewhere. ROI does not automatically account for what you could have earned with the next-best alternative.

Cash Flow Timing Is Overlooked

ROI treats all profits as if they arrive at one point in time. In reality, investments generate cash flows at different intervals. A project that returns money early is more valuable than one that returns the same total amount years later, because early cash can be reinvested. Metrics like Net Present Value (NPV) and Internal Rate of Return (IRR) address this limitation.

It Can Be Manipulated

The definition of "cost" and "profit" is not always straightforward. A business might exclude overhead costs from an ROI calculation to make a project look better. A marketer might attribute all revenue from a multi-touch customer journey to a single campaign. Always clarify what is included in the numerator and denominator.

Complementary Metrics to Use Alongside ROI

To get a complete picture, combine ROI with these additional metrics:

• Net Present Value (NPV) — discounts future cash flows to their present value, accounting for the time value of money. A positive NPV means the investment creates value above your required return rate.
• Internal Rate of Return (IRR) — the annualized rate of return that makes NPV equal to zero. Useful for comparing investments with different cash flow patterns.
• Payback Period — how long it takes to recover the initial investment. Shorter is better, especially for risky ventures.
• Sharpe Ratio — measures return per unit of risk. Higher is better. Essential for comparing investment portfolios.
• Cap Rate — specifically for real estate, it divides net operating income by property value. Useful for comparing properties without considering financing.

How to Improve Your ROI

Regardless of the investment type, there are only two fundamental ways to improve ROI: increase the return or decrease the cost.

For Stock Investments

• Minimize fees by using low-cost brokerages and index funds
• Hold investments long enough to qualify for long-term capital gains tax rates
• Reinvest dividends to benefit from compounding
• Diversify to reduce risk-adjusted returns

For Real Estate

• Add value through strategic renovations that increase rent potential
• Shop for lower interest rates and refinance when rates drop
• Reduce vacancy by maintaining properties well and pricing competitively
• Use cost segregation studies for accelerated depreciation tax benefits

For Marketing

• A/B test ads and landing pages to improve conversion rates
• Focus spending on high-performing channels and audiences
• Increase average order value through upselling and cross-selling
• Improve customer retention to increase lifetime value

Real-World ROI Benchmarks

Knowing what "normal" looks like helps you evaluate whether your ROI is competitive:

• S&P 500 index fund: approximately 10% average annual return over the long term (before inflation)
• Real estate (residential rental): 8–12% total annual return including appreciation and cash flow
• Savings accounts (2024–2026): 4–5% APY for high-yield accounts
• Small business: varies wildly, but successful businesses often target 15–30% ROI on capital expenditures
• Digital marketing: 5:1 return (400% ROI) is considered strong; 2:1 (100%) is the minimum viable threshold
• Venture capital: targets 25%+ annualized returns to offset the high failure rate of startups