How Investment Bankers Use Excel’s IRR Function

How Investment Bankers Use Excel’s IRR Function

In the fast-paced world of finance, Microsoft Excel is essential for financial analysis and decision-making at all levels. Among Excel’s various functions, the Internal Rate of Return (IRR) function is particularly crucial for investment bankers. The IRR function allows investment bankers to evaluate the profitability and viability of investment opportunities with speed and precision.


Understanding the Internal Rate of Return (IRR)

The Internal Rate of Return (IRR) is used to determine whether an investment is profitable. The rate makes a project’s future cash worth zero today. IRR is when ‘future money’ and ‘what you pay’ match up.

While NPV is another critical metric in financial decision-making, IRR offers a distinct advantage. NPV gives a dollar figure, but IRR’s percentage lets you compare investments easily. If Project A’s IRR is 15% and B’s is 10%, Project A seems better.

The IRR function is as follows:

=IRR(values, [guess])


  • values‘ represent the range of cells containing cash flows associated with the investment,
  • [guess]‘ is an optional starting point for Excel’s iterative calculation process.

Create Financial Models 10x Faster with Macabacus

Gain access to 100+ shortcuts, formula auditing visualizations, easy Excel-to-PowerPoint linking and productivity tools to help you accelerate financial modeling and presentations.

Start your Free Trial

The Role of IRR in Investment Banking

Investment bankers depend on the IRR function as it helps them gauge profits, no matter the scenario. They often use IRR to check if projects are worth the cost. They match project returns to costs to advise you going forward.

In private equity, IRR is crucial for checking investments. Investors chase high, quick returns, aiming for 20% IRR or beyond. They use IRR to see if deals will hit their return goals.

For mergers and acquisitions, IRR helps assess a deal’s financial appeal. They use IRR to advise if a buy is worth the risk and cost.

Download Excel Template

Download Template

Download Template

Use IRR Function

Try Macabacus for free to accelerate financial modeling in Excel.

Step-by-Step Guide to Using IRR in Excel

Organizing your financial data is essential for the IRR function to be effective, clear, and consistent. Creating a cash flow table involves creating columns for time periods and corresponding cash flows.

Here’s a step-by-step guide to calculating IRR in Excel:

Step 1: Create two tables for the time period and the cash flows in a new Excel spreadsheet.

Step 2: List each time increment in ascending order in the time period column. Start with 0 for the initial investment.

Step 3: Use negative numbers for cash outflows and positive numbers for cash inflows in the cash flow column.

Step 4: Once your cash flow table is complete, select an empty cell where you want the IRR to appear.

Step 5: In that cell, type =IRR( and select the cells containing your cash flow data.

Step 6: Close the parentheses and press ‘Enter’.

The IRR for your investment will be calculated and displayed.

Excel would then calculate and return an IRR of approximately 20%.

What does the above IRR tell us about the investment? The investment is expected to generate a 20% annual return over its five-year life, assuming projected cash flows occur. The said IRR figure is very attractive for a private equity firm targeting high returns. It could prompt the firm to proceed with the investment, subject to other factors such as risk assessment and market conditions.

Pro Tip: Always double-check that your cash flows are inputted correctly, with outflows as negative numbers and inflows as positive numbers. A single mistyped number can throw off your entire IRR calculation.

Common Mistakes and Misconceptions

  • While the IRR function in Excel is a powerful tool, it also comes with pitfalls. One common mistake is mismatching the signs of cash flows, such as entering a positive number instead of a negative number. Such an error can completely distort the IRR calculation and lead to incorrect conclusions about an investment’s profitability.
  • Another potential issue arises when an investment comes with multiple IRRs. It can occur when positive and negative cash flows are interspersed throughout the investment’s life. Excel will only provide a partial picture of the investment’s profitability in such cases.
  • The IRR assumes that intermediate positive cash flows are reinvested at the calculated IRR. The reinvestment rate may be different (often lower) than the IRR, which can overstate the investment’s true profitability.
  • To avoid errors, investment bankers should review cash flow inputs and consider IRR alongside other financial metrics and qualitative factors. Sensitivity analysis tests how changes in assumptions impact the IRR, providing a better understanding of potential returns.

Advanced Uses of IRR in Complex Deals

While the basic use of IRR is relatively straightforward, investment bankers often apply the metric more sophisticatedly, particularly in complex transactions like leveraged buyouts (LBOs) and intricate mergers and acquisitions.

In a leveraged buyout (LBO), a private equity firm acquires a company using significant debt. The objective is to enhance the company’s operations and financial performance in preparation for selling it at a profit. The internal rate of return (IRR) assesses investment returns and considers the impact of leverage. Investment bankers use different debt structures and associated cash flows to optimize the IRR of an LBO transaction.

In complex M&A deals with multiple stages or contingent payments, IRR can evaluate the financial implications of different deal structures. An acquisition may include initial and subsequent payments based on the acquired company’s milestones. Investment bankers can advise clients on deal structure by modeling cash flows and calculating IRR under different scenarios.

In complex scenarios, investment bankers often need to adjust IRR calculations for fluctuating or uncertain cash flows, using probability-weighted cash flows or running multiple IRR scenarios based on different cash flow assumptions. By understanding how changes in cash flow assumptions impact IRR, bankers can make more informed recommendations, helping clients navigate high-stakes transactions.


The IRR function in Excel is a vital tool for investment bankers. It condenses investment profitability into a single, comparable metric, making it valuable for evaluating projects and investment opportunities.

However, as with any tool, the effectiveness of IRR depends on the user’s skill and knowledge. Investment bankers must meticulously project cash flow, understand IRR assumptions and limitations, and interpret results in the broader transaction context.

As finance evolves, mastering tools like IRR becomes more critical. Understanding and using IRR in Excel is necessary for investment bankers, not just an advantage. Advanced productivity tools like Macabacus can significantly improve accuracy and efficiency in financial modeling and analysis. Investment bankers can maximize their use of IRR by honing their skills and using Macabacus, enabling them to make impactful financial decisions.

Create Financial Models 10x Faster with Macabacus

Gain access to 100+ shortcuts, formula auditing visualizations, easy Excel-to-PowerPoint linking and productivity tools to help you accelerate financial modeling and presentations.

Start your Free Trial

Discover more topics

Build an operating model
In this tutorial, we will walk through how to build a general industry business operating model.
Read more
Build an M&A model
In this section, we demonstrate how to model a merger of two public companies in Excel.
Read more
Build an LBO model
In this tutorial, we will walk you through building an LBO model in Excel.
Read more
Asset and Stock Deals
The first step in purchase price allocation, or PPA, is to determine the purchase price.
Read more