Internal Rate of Return — find the discount rate that makes net present value zero.
Enter as negative (e.g., -10000 for an outflow)
Enter each year's cash inflow (positive) or outflow (negative)
Internal Rate of Return
18.03%
Total Cash Inflow$15,000
Net Profit$5,000
Number of Periods4
NPV at 10%$1,839
IRR is the discount rate at which the net present value of all cash flows equals zero. It represents the annualized rate of return on your investment.
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What is the IRR Calculator?
Internal Rate of Return (IRR) is the discount rate at which the sum of discounted cash inflows equals the initial investment (outflow). It's the annual percentage return your investment generates, accounting for the timing and size of every cash flow. IRR is widely used by investors, corporate finance teams, and project managers to rank opportunities and decide whether to proceed with an investment.
How it works
The calculator uses the bisection method to solve for the IRR—the rate where NPV (Net Present Value) equals zero. You provide the initial investment (usually negative) and a stream of annual cash inflows or outflows. The tool iterates through discount rates until it finds the exact rate at which all future cash flows, when discounted back to today, add up to precisely zero. This rate is your IRR.
CF = cash flow in each year; r = discount rate (IRR); n = year number. Each future cash flow is discounted by dividing it by (1 + r) raised to the power of its year. The IRR is the specific value of r that makes the total NPV equal zero.
Your $10k investment returns $3–5k per year for 4 years. The 7.71% IRR means this project yields about 7.71% annual return. Compare to your hurdle rate (e.g., 10% minimum) to decide.
A 3-year European project returning €65k on a €50k investment. 8.53% IRR tells you this project beats a savings account (2–3%) but lags stock markets (10%+).
A larger Indian project returning ₹150k on ₹100k capital over 4 years. At 10.24% IRR, this beats most fixed deposits (6–7%) and aligns with conservative stock-market expectations.
How to use the IRR Calculator
Select your currency (USD, EUR, GBP, or INR) from the dropdown.
Enter the Initial Investment as a negative number (e.g., -10000 for a $10,000 cash outflow at Year 0).
Enter Annual Cash Flows—one per line, as positive (inflow) or negative (outflow) numbers for Years 1, 2, 3, etc.
Click Calculate to compute the IRR, total inflows, net profit, and NPV at 10%.
Compare your IRR to your required rate of return (hurdle rate). If IRR > hurdle rate, the project is likely worth doing.
Review the NPV at 10% statistic—a positive NPV at your cost-of-capital rate confirms the investment adds value.
Benefits
Single metric for comparison: IRR lets you rank multiple projects by a single number, making decision-making faster and clearer.
Accounts for timing: Unlike simple payback period, IRR factors in when each dollar arrives—a $1k inflow today is worth more than one in 5 years.
Actionable benchmark: Compare your IRR to your cost-of-capital or hurdle rate. IRR > cost of capital means the investment creates value.
Works for any pattern: IRR handles irregular cash flows (some years positive, some negative) and uneven amounts—no need for equal annual returns.
Intuitive to executives: A single percentage is easier to explain to stakeholders than a complex NPV calculation.
Guides capital allocation: When capital is limited, rank projects by IRR (highest first) to allocate funds to the best opportunities.
Tips & common mistakes
Common mistakes
Reversing the sign of initial investment: Initial outflows must be negative (e.g., -$50k). If you enter +$50k, the math breaks.
Confusing IRR with profit: A 15% IRR on a 3-year project doesn't mean you keep 15% of the capital. IRR is an annualized return rate, not the total profit.
Ignoring the scale of capital: A project with 30% IRR might tie up $1M and return only $100k; a 10% IRR on $10M is worth more. Always compare scale too.
Forgetting to align time periods: If your cash flows are quarterly, annualize them or adjust the formula. IRR assumes annual periods.
Relying on IRR alone for risky projects: High IRR can hide high risk. Always pair IRR with risk assessment—a 50% IRR is worthless if the project fails.
Missing reinvestment assumptions: Classic IRR assumes all interim cash flows are reinvested at the IRR rate itself, which may be unrealistic. Use MIRR (Modified IRR) for a better estimate if available.
Tips
Set a hurdle rate (minimum IRR you'll accept) before analyzing projects. For corporations, this is often 10–15%; for startups, 20%+; for conservative investors, 6–8%.
Use IRR alongside NPV: IRR tells you the percentage return; NPV tells you the dollar impact. Together they paint the full picture.
Watch for multiple IRRs: Unusual cash flow patterns (multiple sign changes) can produce more than one IRR. If you see this, lean on NPV instead.
Stress-test cash flow assumptions: Small errors in forecasting become big errors in IRR. Test optimistic, base, and pessimistic scenarios.
Compare apples-to-apples: Use the same time horizon and assumptions (inflation, discount rates) when comparing projects by IRR.
Monitor actual vs. forecast: Once the project begins, track real cash flows and recalculate IRR. If it's tracking below expectations, investigate early.
Frequently asked questions
What's the difference between IRR and ROI (Return on Investment)?
ROI is a simple percentage: (Gain − Cost) / Cost. IRR accounts for the timing of cash flows and solves for the discount rate where NPV = 0. IRR is more precise for multi-year projects; ROI is simpler for one-off investments.
Can IRR be negative?
Yes. If cash outflows exceed inflows or the inflows are delayed too long, IRR can be negative—meaning you're losing money in annualized terms. This signals a bad investment.
What if the calculator shows 'No valid IRR'?
This happens when the cash flows never produce an NPV of zero (e.g., all positive flows with no initial investment, or extreme sign oscillations). Check that your initial investment is negative and inflows are positive.
How do I use IRR to choose between two projects?
Pick the project with the higher IRR, provided it exceeds your hurdle rate. If one is high-IRR/high-risk and the other is low-IRR/low-risk, compare alongside NPV and risk tolerance. Higher IRR is not always better if capital or risk is unbalanced.
What's the relationship between IRR and the discount rate?
IRR is the discount rate at which NPV = 0. Your company's discount rate (cost of capital) is usually lower—e.g., 8%. If a project's IRR is 12%, its NPV at 8% discount will be positive, confirming the project adds value.
Should I use NPV or IRR for final decisions?
NPV is generally superior: it shows absolute dollar value added. IRR is handy for ranking small, similar projects. For large capital decisions, always compute both and use NPV as the tie-breaker when IRRs are close.