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IRR Calculator
For any series of cash flows, this IRR calculator solves the internal rate of return, adds a dated XIRR mode for irregular calendar dates, and shows NPV and MIRR alongside — with the exact point where NPV crosses zero.
See how this works on a $10,000 project paid back three ways — 3 real examples
Internal rate of return (IRR)
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NPV @ 8%
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Modified IRR (MIRR)
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Net cash flow
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NPV profile — where NPV crosses zero is the IRR
Net present value at each discount rate (equal periods). The dashed line marks your discount rate.
Cash-flow scheduleEach flow discounted to present value
How we solve for your internal rate of return
IRR is the rate i that makes the net present value of every cash flow equal zero:
NPV(i) = Σ CFt / (1 + i)t = 0 (t = 0, 1, 2, …)
XIRR: exponent = (datet − date0) / 365
MIRR = (FV+ @ reinvest / −PV− @ finance)1/n − 1
There is no closed form for i, so we solve numerically: the engine scans the range from about −99% to +1000% for the first sign change in NPV, then bisects to the root. In Regular mode every flow sits one equal period apart (t = 0, 1, 2…). In Dated (XIRR) mode the exponent becomes the exact number of days since the first flow, divided by 365 (Actual/365), so irregular dates are annualized correctly. NPV and the discounted column of the schedule always use equal periods and reconcile to the engine’s NPV figure; XIRR uses your exact dates.
If the flows never change sign there is no IRR (a pure loss or pure gain), and if they change sign more than once several IRRs can exist — we return the lowest and point you to MIRR, which grows positive flows forward at the reinvestment rate and discounts negative flows back at the finance rate for a single figure. This tool is for education and planning, not investment advice.
One investment, three payback schedules
Three projects each turn $10,000 into $16,200 over four years. The only difference is which year the money comes back.
Most of it back in year one
IRR36.14%
- The schedule runs $9,200, $4,000, $2,000, then $1,000 — cash returns almost at once.
- Early dollars can be put back to work, and the IRR credits that at 36.14%.
- At an 8% hurdle the project is worth $4,271 today, the highest of the three.
Same total as the other tabs, but the calendar hands this version the best rate.
Load this example (opens in a new tab)The default: rising, then easing off
IRR21.18%
- Cash arrives as $3,000, $4,200, $5,000 and $4,000 — heaviest in the middle years.
- The internal rate of return works out to 21.18%, with $3,288 of value at an 8% hurdle.
- MIRR, which reinvests interim cash at a stated 10% instead, reads a more sober 16.74%.
A middle-weighted schedule earns a middle rate — the pattern decides, not the total.
Load this example (opens in a new tab)The same money, arriving late
IRR15.97%
- Reversing the first schedule — $1,000, $2,000, $4,000, $9,200 — drops the IRR to 15.97%.
- Waiting shrinks present value too: $2,578 at an 8% hurdle, against $4,271 up front.
- Every dollar matches the first tab; only the order of arrival has changed.
$6,200 of profit either way — the wait is what costs some twenty points of IRR.
Load this example (opens in a new tab)Illustrations only, not financial advice. Your own rate, taxes and insurance will differ — check with a qualified financial advisor before acting on any of this.
Reading an IRR, in plain English
- IRR is timing-aware. Unlike ROI, it rewards cash that comes back sooner — a dollar in year 1 is worth more than the same dollar in year 5.
- Compare it to your hurdle rate. An IRR above your cost of capital adds value; below it, the project loses money even if the number looks positive. The NPV-at-your-rate tile is the honest tie-breaker.
- Use XIRR for real dates. Rent checks, capital calls and distributions rarely land exactly a year apart — dated mode annualizes by the actual days so the return isn’t overstated or understated.
- Watch for multiple sign changes. An outflow → inflows → outflow pattern can produce more than one IRR; when that happens, trust MIRR.
- MIRR is more realistic. Plain IRR assumes you reinvest interim cash at the IRR itself; MIRR lets you set a sensible reinvestment rate instead.
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Frequently asked questions
What is the internal rate of return (IRR)?
The internal rate of return is the discount rate at which the net present value (NPV) of every cash flow — the up-front outflow and all later inflows — equals exactly zero. It is the annualized return the project earns on the money still invested in it. For the default series (−$10,000 then $3,000, $4,200, $5,000 and $4,000), the IRR is about 21.4%: discount those inflows at 21.4% and they sum back to the $10,000 you put in.
What is the difference between IRR and XIRR?
IRR assumes every cash flow is one equal period apart (typically one year). XIRR uses the exact calendar dates you enter and annualizes with an Actual/365 day-count, so it is accurate when money arrives on irregular dates — a payment on March 3 is weighted differently than one on December 20. Flip this tool to “Dated (XIRR)” mode, give each flow a real date, and it switches from the equal-period irr formula to xirr. Most competitor tools only do the equal-period version.
How is IRR different from ROI?
ROI is a simple total-gain percentage: net profit divided by cost, ignoring when the money moved. IRR is the annualized rate that accounts for the timing of every cash flow, so $5,000 received in year 1 counts for more than the same $5,000 in year 5. Two projects can share an ROI of 62% yet have very different IRRs if one returns cash sooner. Use ROI for a quick headline and IRR when timing matters.
What is a good IRR?
An IRR is “good” only relative to your cost of capital or required rate of return (your hurdle rate). If financing and opportunity cost run about 8%, a project with a 21% IRR clears the bar comfortably and adds value; one at 5% destroys value even though the number is positive. That is why this calculator shows NPV at a discount rate you set alongside the IRR — a positive NPV at your hurdle rate is the real green light.
Why can a project have multiple IRRs?
When the cash flows change sign more than once — for example an outflow, then inflows, then a large closing outflow — the NPV equation is a higher-order polynomial that can cross zero at several rates, so more than one IRR mathematically satisfies NPV = 0. This tool flags that case and reports the first (lowest) root. When it appears, lean on MIRR, which returns a single unambiguous figure.
What is MIRR and why use it?
Modified IRR (MIRR) fixes two weaknesses of plain IRR: it assumes interim inflows are reinvested at a realistic reinvestment rate you choose (not at the IRR itself) and outflows are financed at a separate finance rate, and it always returns a single value even with multiple sign changes. It grows the positive flows forward at the reinvestment rate, discounts the negative flows back at the finance rate, and annualizes the ratio. Set both rates in the inputs to see it.
How do NPV and IRR work together here?
NPV and IRR are two views of the same math. NPV discounts every cash flow at a rate you pick and sums them; IRR is the one rate that makes that sum zero. The NPV profile chart plots NPV across a range of discount rates — where the curve crosses the zero line is the IRR. Slide the discount rate to see NPV rise as your required return falls, and note that NPV and the discounted schedule use equal periods while XIRR uses your exact dates.
Disclaimer: these calculators are educational tools, not financial advice. They model your inputs with published formulas, but they cannot know your full situation — for decisions with real stakes, talk to a qualified professional. Formulas and defaults last reviewed .