💹 IRR Calculator
Internal rate of return for evenly spaced or dated cash flows (XIRR), with NPV, MIRR, payback, an NPV chart and a warning when there are multiple IRRs.
Money you put in is negative; money you get back is positive.
| NPV at 8% | 605.36 |
|---|---|
| MIRR | 9.60% |
| Total in | 13,000.00 |
| Total out | 10,000.00 |
| Money multiple (in ÷ out) | 1.30× |
| Payback | 3.25 years |
| Discounted payback at 8% | 3.79 years |
NPV profile: where the curve crosses the gray zero line (red dots) is the IRR.
What IRR Calculator Does
This IRR calculator finds the internal rate of return of any series of cash flows — the single rate at which the money you put in grows into the money you get back. Enter the initial investment as a negative number and each later cash flow in order, for yearly, half-yearly, quarterly or monthly periods, or switch to dates for irregular timing to get the XIRR that spreadsheets use.
Alongside the IRR you get the net present value at your discount rate, the modified IRR (MIRR), the simple and discounted payback periods, the totals in and out, and a chart of NPV across discount rates. The calculator searches the whole range of rates, so if your cash flows produce two IRRs — or none — it tells you, rather than showing one misleading number.
How to Use IRR Calculator
- Choose evenly spaced cash flows (IRR) or specific dates (XIRR)
- Enter the initial investment as a negative number
- Add each later cash flow — or paste a column from a spreadsheet
- Set a discount rate for NPV and, optionally, MIRR rates
- Read the IRR, NPV, MIRR, payback and the NPV profile chart
Formula Used by IRR Calculator
Internal rate of return
0 = Σ CFₜ ÷ (1 + IRR)ᵗ, for t = 0, 1, 2, …
Worked example
Invest 10,000, then receive 2,500, 3,000, 3,500 and 4,000 over four years.
- NPV at 10% = +114; NPV at 11% = −119
- The zero crossing is at 10.48%
- NPV at an 8% discount rate = +605
Result: IRR = 10.48%; payback after 3.25 years.
Annualizing a periodic IRR
Annual IRR = (1 + periodic IRR)ᵏ − 1, where k = periods per year
Worked example
Monthly cash flows with an IRR of 1% per month.
- (1.01)¹² − 1 = 0.1268
Result: 12.68% a year effective, or 12% nominal.
IRR, NPV, MIRR and Payback Compared
| Measure | What it tells you | Watch out for |
|---|---|---|
| IRR | The break-even discount rate, as a % | Multiple or no IRRs; assumes reinvestment at the IRR |
| NPV | Value added in today’s money at your rate | Depends on choosing the right discount rate |
| MIRR | A return using realistic finance and reinvestment rates | Needs two extra rates |
| Payback | How long until you get your money back | Ignores everything after payback |
Example Cash-Flow Patterns
| Pattern | Cash flows | IRR |
|---|---|---|
| Invest once, returns later | −1,000, 300, 400, 500 | 8.90% |
| Returns fall short | −1,000, 300, 300, 300 | −5.09% |
| Two sign changes | −100, 230, −132 | 10% and 20% |
| Money in first (a loan) | +1,000, −1,100 | 10% — a borrowing cost |
How to Read Your Result
IRR or NPV?
For a single project with money out first and money in later, an IRR above your hurdle rate and a positive NPV at that rate always agree. When you compare projects of different sizes or lengths they can disagree; NPV shows which adds more value in dollars, so use it to choose between them.
The reinvestment assumption
IRR implicitly assumes interim cash flows are reinvested at the IRR itself. For a project with a very high IRR that is rarely realistic, which is why MIRR — using the rate you could actually earn — is usually lower and more conservative.
Property and fund investments
For real estate or private investments with contributions and distributions on specific dates, use the dated XIRR mode so the timing is exact. Enter the sale proceeds, net of selling costs, as the final positive cash flow.
Limitations & Accuracy Notes
- Rates are searched between −99.99% and 10,000% a year; IRRs outside that range are not reported.
- MIRR and payback are shown for evenly spaced cash flows only.
- Taxes, fees and inflation are not modeled; enter after-tax, after-fee cash flows to include them.