IRR Calculator — Internal Rate of Return for Projects and Investments
Calculate Internal Rate of Return (IRR) for any series of cash flows. Find the break-even discount rate that makes an investment's NPV equal to zero.
IRR is the annual return percentage that makes an investment break even in NPV terms — the discount rate at which all future cash flows, when discounted back to today, exactly equal the initial investment. If IRR exceeds your cost of capital, the investment creates value. The CalcHub IRR Calculator finds this rate iteratively from any set of cash flows.
How IRR Works
There's no closed-form formula for IRR — it's found by solving NPV = 0:
0 = −Initial Investment + Σ [Cash Flow_t / (1 + IRR)^t]You're finding the discount rate (r) that makes that equation true. This requires iterative calculation, which is why calculators are essential.
Example: Evaluating a Business Expansion
A restaurant owner considers opening a second location. Cash flows:
| Period | Cash Flow |
|---|---|
| Year 0 (investment) | −₹25,00,000 |
| Year 1 | +₹4,00,000 |
| Year 2 | +₹6,00,000 |
| Year 3 | +₹8,00,000 |
| Year 4 | +₹10,00,000 |
| Year 5 | +₹12,00,000 + ₹15,00,000 (sale value) |
If the restaurant owner's cost of capital (what else they could do with ₹25L) is 15%, this expansion is a good investment — it earns 24.8% annually. If their alternative is a 30% return, they'd skip it.
IRR vs Required Rate of Return
| Scenario | IRR | Required Return | Decision |
|---|---|---|---|
| Marketing investment | 45% | 15% | Strong yes |
| New equipment | 18% | 20% | No — destroys value |
| Product development | 12% | 12% | Indifferent |
| Real estate | 14% | 10% | Yes |
How to Use the Calculator
- Enter the initial investment (Year 0, negative)
- Enter cash flows for each subsequent period (positive or negative)
- Click calculate — the tool solves for IRR iteratively
- Compare result to your hurdle rate
Limitations of IRR
IRR is powerful but has well-documented weaknesses:
Multiple IRRs: When cash flows change sign more than once (positive, then negative, then positive), there can be multiple IRRs. The calculator may not return a meaningful answer. Use NPV in these cases. Scale blindness: A small project with 80% IRR may create less value than a large project with 25% IRR. IRR doesn't reflect investment size, only percentage return. Use IRR alongside NPV for a complete picture. Reinvestment assumption: IRR implicitly assumes all interim cash flows are reinvested at the IRR rate. This is often unrealistic for very high IRRs. Modified IRR (MIRR) uses a more realistic reinvestment rate.When IRR Is Most Useful
- Comparing investments of similar size and duration
- Private equity and venture capital portfolio decisions
- Real estate investment analysis
- Explaining to non-finance stakeholders (percentage return is intuitive)
What's a good IRR for a startup investment?
Early-stage venture capital typically targets 30–50%+ IRR to account for the high failure rate across a portfolio. Later-stage growth equity might target 20–30%. Real estate private equity often targets 15–25% IRR. "Good" depends heavily on risk profile and asset class — higher risk should demand higher IRR.
How is IRR different from CAGR?
CAGR (Compound Annual Growth Rate) measures the growth rate between two specific points (beginning and end value). IRR accounts for the timing and magnitude of all intermediate cash flows. For an investment with a single initial outflow and single final inflow, IRR and CAGR are mathematically equivalent. For multiple cash flows, they diverge.
Why does IRR sometimes return no solution?
If all cash flows are negative, there's no rate that makes NPV = 0 — the investment is always a loss. Some iterative solvers also fail to converge for unusual cash flow patterns. If the calculator doesn't return an IRR, check your cash flow signs and consider whether NPV analysis is more appropriate.