How to Use Goal Seek in LibreOffice Calc

LibreOffice Calc features a built-in “Goal Seek” tool designed for what-if analysis, allowing you to determine the exact input value needed to achieve a specific target result in a formula. This step-by-step guide explains how to set up your spreadsheet, configure the Goal Seek parameters, and automatically calculate your desired outcome.

Understanding the Goal Seek Requirements

To use Goal Seek successfully, your spreadsheet must contain three elements:

1. Formula Cell: A cell containing an active formula that calculates a result.
2. Target Value: The specific numerical outcome you want the formula to reach.
3. Variable Cell: An input cell containing a plain number (not a formula) that the formula references directly or indirectly.

Step 1: Set Up Your Data

Set up your basic scenario in a Calc sheet. For example, to calculate total revenue:

• Cell A2 (Units Sold): 50
• Cell B2 (Price per Unit): 20
• Cell C2 (Total Revenue): =A2*B2 (Displays $1,000)

In this scenario, suppose you want Total Revenue (Cell C2) to reach $2,500 by changing the number of Units Sold (Cell A2).

Step 2: Open the Goal Seek Tool

1. Select the cell with the formula you want to evaluate (e.g., C2).
2. Navigate to the top menu and click Tools.
3. Select Goal Seek… from the dropdown menu.

Step 3: Configure the Goal Seek Dialog

Fill in the three fields in the Goal Seek window:

• Formula cell: Enter the reference for your formula cell (e.g., C2 or $C$2). If you selected the cell before opening the tool, this field will be populated automatically.
• Target value: Type the exact numerical result you want to achieve (e.g., 2500).
• Variable cell: Enter the cell reference that Calc should modify to reach the target (e.g., A2 or $A$2). You can also click the cell directly on the sheet to insert its reference.

Step 4: Run the Calculation

1. Click OK.
2. A dialog box will appear stating: “Goal Seek successful. Insert result (125) into current cell?”
3. Click Yes to replace the original value in the variable cell with the new calculated value.
4. Click No if you only wanted to view the required value without modifying your spreadsheet data.