IRR Calculator

Estimate the Internal Rate of Return (IRR) for an investment with equal annual cash flows using bisection. Free, instant, no signup.

years
Formula: NPV(r) = −Investment + Σ Cashflow/(1+r)^t = 0 → solve for r
  • r = IRR (solved by bisection)
  • t = year index 1..n

How to use the IRR Calculator

  1. Enter your values. Fill in the fields with your numbers.
  2. Calculate. Press Calculate to run the irr calculator.
  3. Use the result. Copy the result or try a related tool next.

Why use our IRR Calculator

Instant results. Enter your figures and the irr calculator returns an answer in seconds.
Free & private. Runs in your browser — no signup, and nothing is sent to a server.
Accurate. Uses standard formulas so you can rely on the numbers.

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About the IRR Calculator

The IRR Calculator finds the internal rate of return for a series of cash flows: the single annualized discount rate that makes the net present value of every inflow and outflow equal zero. You enter your initial outlay (a negative number, since money leaves your pocket) followed by each period's cash flow, and the tool returns the percentage rate at which the investment exactly breaks even in present-value terms. Because IRR bakes the timing of money into one figure, it is the standard yardstick for comparing projects, property deals, private-equity funds, and any plan where cash arrives unevenly over several years rather than as a single lump sum.

Reach for this calculator whenever you need to judge a multi-year investment by a single comparable number. Real-estate investors use it to score a buy-and-hold deal against a target like 8-10% for stable core assets or 15%+ for value-add plays; business owners use it to rank capital projects against their cost of capital, funding only those whose IRR clears the hurdle rate. It is also handy for sense-checking a fund's quoted return or comparing two offers with different payout schedules. Note that IRR rewards early cash: a 50% total gain over two years works out to roughly 22% IRR, while the same 50% spread over five years is only about 8%.

Under the hood, IRR cannot be solved with a single algebraic step, so the calculator solves it iteratively. It starts from a guess (often 10%), computes the NPV of your cash flows at that rate, and then refines the rate, narrowing on the value where NPV crosses zero using a Newton-Raphson or interpolation routine, exactly how spreadsheet IRR functions work. One caveat built into the math: standard IRR implicitly assumes interim cash flows are reinvested at the IRR itself, which can flatter high-return deals. When cash flows switch sign more than once, more than one rate can satisfy the equation, the well-known multiple-IRR problem, in which case MIRR or NPV is the safer guide.

Everything is computed in your browser. Your cash-flow figures are never uploaded, logged, or stored on a server, so you can model sensitive deal numbers privately and reload the page to start fresh. The result is a mathematical solution to your exact inputs, so its accuracy depends entirely on the realism of your cash-flow estimates and on using a consistent period length (yearly figures give an annual IRR; monthly figures give a monthly rate you must annualize). For sign-changing or unconventional cash-flow patterns, cross-check the answer against NPV at your own discount rate before acting on it.

Frequently asked questions

What is a good IRR?

It depends on the risk and the alternative uses of your money: an IRR only adds value when it beats your hurdle rate or cost of capital. In real estate, roughly 8-10% is typical for stable core assets and 15%+ for higher-risk value-add deals, but a 12% IRR on a safe project can beat a 20% IRR on a risky one.

How do I enter cash flows in the IRR Calculator?

Enter your initial investment as a negative number (cash going out), then list each later period's net cash flow with its correct sign, positive for money received, negative for further outlays. The periods must be equally spaced, and the IRR you get matches that spacing, so yearly figures produce an annual rate.

What is the difference between IRR and NPV?

NPV gives you a dollar value of an investment at a discount rate you choose, while IRR is the specific discount rate that drives that NPV to zero. They answer related questions, and when comparing mutually exclusive projects NPV is generally the more reliable decision rule.

Why does the calculator return more than one IRR, or none at all?

When your cash flows change sign more than once (for example, an outflow, then inflows, then another large outflow), the underlying equation can have multiple valid solutions or none. In those cases IRR is unreliable, so use NPV at your own discount rate or the modified IRR (MIRR) instead.

Does IRR assume I reinvest the cash I receive?

Yes, the standard IRR formula implicitly assumes every interim cash flow is reinvested at the IRR itself, which can overstate the return on high-IRR deals. If that assumption is unrealistic, MIRR lets you reinvest at a more conservative rate such as your cost of capital.

From our blog

Cubic Feet, Made Simple: Measuring Volume for Moving, Shipping and Storage

By the Super Simple Digital Tools Team · Updated June 2026

Cubic feet is one of those measurements you rarely think about until you are standing in front of a stack of boxes wondering whether they will fit in the truck. A cubic foot is simply the volume of a cube that measures one foot on every side. Multiply that out and a single cubic foot equals 1,728 cubic inches, or about 28.3 litres. Once that picture is in your head, every cubic-feet calculation is just a question of how many of those one-foot cubes would fill the space you are measuring.

The arithmetic never changes: length times width times height. What trips people up is units. A tape measure usually reports inches, furniture catalogues often use inches too, and European appliances list centimetres, yet the answer you want is in feet. The clean approach is to convert each side to feet first, then multiply. The shortcut for inches is to multiply the three raw numbers and divide by 1,728. For centimetres, work in cubic centimetres and divide by 28,316.8. The calculator does whichever conversion you need so you never have to remember the factor.

Movers lean on cubic feet because rental trucks and shipping containers are rated that way. Add up the volume of your boxes and large items, compare it to the truck's rated capacity, and you avoid both the trip back for a second load and paying for half-empty space. A rough rule is that a fully packed standard moving box is around 3 to 4.5 ft³, so even a quick tally of box sizes gets you a usable estimate before you book anything.

In shipping and freight the number does double duty. Beyond fitting items into a container, carriers convert volume into a dimensional or volumetric weight and bill whichever is greater, the real weight or the volumetric one. Lightweight but bulky parcels — pillows, lampshades, packing foam — are priced on their cubic feet, not their pounds. Calculating volume first lets you see that coming and sometimes repack into a smaller box to drop a price tier.

Around the house and yard the same tool keeps showing up. Refrigerator and freezer capacity is quoted in cubic feet, so measuring the interior tells you whether a model truly holds more than your current one. Garden soil, mulch and gravel are sold by the cubic foot or cubic yard, and since one cubic yard is exactly 27 cubic feet, a quick volume figure converts straight into how many bags to buy. The skill transfers everywhere because volume is volume, whatever you are filling.

  • Decide up front whether you need interior or exterior dimensions — inside space for what fits, outside space for shipping or footprint.
  • When measuring in inches, you can multiply all three sides and divide by 1,728 in one step rather than converting each side separately.
  • For an irregular item, break it into simple boxes and cylinders, calculate each piece, and add the volumes together.
  • Remember 1 cubic yard = 27 cubic feet when ordering soil, mulch or gravel so you can switch between the units suppliers use.

Read the full guide →

Tool by the Super Simple Digital Tools Team. Reviewed by our editorial team. Free to use, no signup required.

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