IRR Calculator

Introduction

This IRR Calculator finds the internal rate of return: the discount rate that sets net present value of all cash flows to zero. Enter initial outlay, periodic inflows, and optional terminal value to see annualized IRR. It suits capital projects, rental properties, and private deals with uneven cash timing.

Who this calculator is for

Small business owners evaluating equipment, real estate investors comparing levered deals, and finance students checking homework. Use IRR when cash flows change sign once or follow a clear invest-then-receive pattern.

Simple buy-and-hold with no interim flows is easier on the ROI Calculator or Interest Rate Calculator. Personal accounts with many small deposits fit the Average Return Calculator.

What it estimates

IRR solves for r in sum of CF_t / (1 + r)^t = 0 across all periods t, including negative initial investment and positive later receipts. The result is usually annualized for comparison with hurdle rates and cost of capital. Spreadsheet IRR functions may differ by a few basis points if they assume 365-day years; use this page for consistent teaching examples.

Multiple IRRs can exist if cash flows switch signs more than once (invest, receive, invest again). This tool assumes a conventional pattern unless documented otherwise. Reinvestment at IRR is a theoretical assumption, not a bank rate guarantee. Modified IRR (MIRR) is not calculated here but can rank projects differently when reinvestment rates differ from IRR.

Inputs explained

Enter outflows as negative numbers or use dedicated investment fields per the form. Match period spacing: annual flows need annual IRR; monthly flows need consistent monthly periods before annualizing.

• Initial investment: Up-front cost at time zero (negative cash flow).
• Periodic cash inflows: Equal or varying receipts each period.
• Number of periods: How long inflows continue.
• Terminal / residual value: Sale proceeds or salvage at the end, added to final period.
• Timing: End-of-period receipts unless the tool specifies beginning-of-period.

How to read the results

IRR above your hurdle rate (often weighted average cost of capital or required return) suggests the project clears your bar on a pure NPV=0 basis. Compare two projects at the same scale; higher IRR is not always better if one project is much larger in dollar NPV.

Cross-check with payback on the Payback Period Calculator for liquidity risk. IRR ignores project size: a 25% IRR on $5,000 may add less wealth than 12% on $500,000. Use NPV at your discount rate for scale decisions.

Worked example

Invest $40,000 at time zero. Receive $8,000 at the end of each of years 1 through 6, plus $10,000 residual in year 6 (total year-6 inflow $18,000 if combined). IRR solves near 11% to 13% depending on whether residual stacks on year 6 or is separate.

Total undiscounted cash back is $8,000 x 6 + $10,000 = $58,000 on $40,000 outlay. IRR below the simple 45% naive return because money arrives over six years. That gap is why discounting matters. Sensitivity: drop year-six inflow to $6,000 and watch IRR fall several points.

Practical use cases

Compare solar panel install with utility savings streams. Model franchise fee plus five years of owner cash draws before sale. Screen venture-style deals where you need a quick hurdle check before full spreadsheet modeling.

Pair with Present Value Calculator at your cost of capital to compute NPV explicitly. For bond yield conventions, use Bond Calculator instead of IRR. When two projects have similar IRR but different scale, build a simple NPV table in a spreadsheet using the IRR output as a sanity check only.

Limitations and related tools

Mutually exclusive projects of different length may rank differently under IRR versus NPV (reinvestment assumption debate). Taxes, depreciation shields, and working capital swings are not modeled unless you net them into cash flows.

Simple return on one round trip: ROI Calculator. Time to recover capital: Payback Period Calculator. Full TVM five-key: Finance Calculator. When IRR and NPV disagree on ranking, report both to decision makers along with project scale in dollars.

How It Works

1. Enter initial outlay. Record the investment amount at time zero as a negative flow or dedicated field.
2. Add periodic inflows. Type each period's expected cash in, or equal annual amount and count.
3. Include terminal value. Add resale, salvage, or final balloon to the last period if applicable.
4. Calculate IRR. Click Calculate. Compare IRR to your hurdle rate and run NPV mentally at that rate.

Formula and methodology

The IRR Calculator uses this identity for the scenario you enter. A bank, payroll system, or tax program may round on a 360-day year or average daily balance, so a statement can differ by a small amount.