ROI Calculator
Calculate the Return on Investment (ROI) as a percentage to evaluate the efficiency of an investment. Compares the net gain or loss relative to the initial cost of the investment.
This free online roi calculator provides instant results with no signup required. All calculations run directly in your browser — your data is never sent to a server. Enter your values below and see results update in real time as you type. Perfect for everyday calculations, homework, or professional use.
The total value received from the investment.
The total amount invested.
How to Use This Calculator
Enter your input values
Fill in all required input fields for the ROI Calculator. Most fields include unit selectors so you can work in your preferred unit system — metric or imperial, whichever matches your problem.
Review your inputs
Double-check that all values are correct and that you have selected the right units for each field. Incorrect units are the most common source of calculation errors and can produce results that are off by factors of 2, 10, or more.
Read the results
The ROI Calculator instantly computes the output and displays results with units clearly labeled. All calculations happen in your browser — no loading time and no data sent to a server.
Explore parameter sensitivity
Try adjusting individual input values to see how the output changes. This is a quick and effective way to develop intuition about how different parameters influence the result and to identify which inputs have the largest effect.
Formula Reference
ROI Calculator Formula
See calculator inputs for the governing equation
Variables: All variables and their units are labeled in the calculator interface above. Input fields accept values in multiple unit systems — select your preferred unit from the dropdown next to each field.
When to Use This Calculator
- •Use the ROI Calculator when comparing financial options side-by-side — such as different loan terms or investment returns — to make more informed decisions.
- •Use it to quickly estimate costs or returns before making purchasing, investment, or borrowing decisions.
- •Use it for financial education and planning to understand how compound interest, fees, or tax affects the real value of money over time.
- •Use it when building or reviewing a budget to verify that projections and calculations are mathematically correct.
About This Calculator
The ROI Calculator is a free financial calculation tool designed to help individuals and businesses understand key financial concepts and estimate costs, returns, and loan parameters. Calculate the Return on Investment (ROI) as a percentage to evaluate the efficiency of an investment. Compares the net gain or loss relative to the initial cost of the investment. The calculations are based on standard financial mathematics formulas. Results are for informational and educational purposes only and should not be considered financial, investment, or tax advice. Consult a qualified financial professional before making financial decisions. All calculations are performed in your browser — no personal financial data is stored or transmitted.
About ROI Calculator
The Return on Investment (ROI) calculator measures the profitability of an investment by expressing the net gain or loss as a percentage of the initial cost. ROI is one of the most widely used financial metrics because of its simplicity and versatility. It is used to evaluate stock purchases, real estate deals, marketing campaigns, equipment upgrades, and business projects. A positive ROI means the investment earned more than it cost, while a negative ROI indicates a loss. While ROI does not account for time (a 50% ROI over 1 year is very different from 50% over 10 years), it provides a quick snapshot of investment efficiency that is easy to communicate to stakeholders.
The Math Behind It
Formula Reference
ROI Formula
ROI = ((Gain - Cost) / Cost) * 100
Variables: Gain = final value or total revenue; Cost = initial investment
Worked Examples
Example 1: Stock investment
You bought shares for $10,000 and sold them for $15,000.
The ROI is 50%, meaning the investment earned half its cost in profit.
Example 2: Marketing campaign
A $5,000 campaign generated $18,000 in revenue.
The marketing ROI is 260%.
Common Mistakes & Tips
- !Comparing ROIs of investments with different time horizons without annualizing.
- !Excluding significant costs (opportunity cost, taxes, fees) from the cost figure.
- !Using ROI as the sole decision criterion without considering risk and liquidity.
Related Concepts
Used in These Calculators
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Frequently Asked Questions
What is a good ROI?
It depends on the context. The S&P 500 historically returns about 10% per year. Any ROI above the risk-free rate (Treasury bonds) plus a risk premium can be considered acceptable.
Can ROI be negative?
Yes. A negative ROI means the investment lost money. For example, buying stock for $10,000 and selling for $8,000 gives an ROI of -20%.
How is ROI different from profit margin?
ROI measures return relative to the investment cost. Profit margin measures profit relative to revenue. They answer different questions about profitability.