How to Create a Parameter in Tableau

Ever wish you could give the users of your report a way to interact with the data and explore it on their own terms? Tableau parameters are the key to unlocking that experience, transforming your static charts into interactive dashboards. This guide will walk you through exactly what parameters are, how to create them step by step, and how to use them to supercharge your visualizations.

What Exactly is a Tableau Parameter?

Think of a Tableau parameter as a dynamic placeholder or a variable. It's a value that you, or more importantly, your end-user, can change at will. Unlike filters, which limit the data based on existing values within a field, a parameter is an independent value that doesn't do anything on its own. Its real power comes to life when you link it to a calculated field, a filter, or a reference line.

Here's a simple way to think about the difference:

• A filter is like choosing an option from a fixed dropdown menu. If you filter by the "Region" field, you can only choose from existing regions like "West," "East," or "Central."
• A parameter is like a blank text box in a form. You can enter a specific number, select a date, or choose from a list you create. That input then drives calculations or other elements in your dashboard.

In short, filters help users see a smaller slice of the existing data, while parameters let them input custom values to see different scenarios, measures, or dimensions altogether.

Why Should You Use Parameters?

Parameters are fundamental to building user-centric dashboards. They empower your audience to explore data in a way that's meaningful to them. Here are the biggest benefits:

• Enhanced Interactivity: Parameters make dashboards feel less like static reports and more like an interactive application. Users can play with the data, test assumptions, and discover insights without needing you to create a dozen different versions of the same chart.
• "What-If" Analysis: Have you ever wanted to know what would happen if sales increased by 15% next quarter? Parameters make this easy. You can create a slider that allows the user to input a percentage and instantly see the projected outcome, turning a simple chart into a forecasting tool.
• Increased Flexibility: Instead of building separate charts for sales, profit, and quantity, you can use a parameter to let the user switch between these measures within a single chart. This saves valuable dashboard real estate and simplifies the user experience.

A Step-by-Step Guide to Creating a Parameter

Creating a parameter is a straightforward process. The magic isn't just in creating it, but in how you link it to your worksheet. First, let's nail down the creation steps.

1. Open the Create Parameter Dialog Box

In the Data pane on the left side of your Tableau worksheet, right-click anywhere in the empty space below your data sources and select Create Parameter....

This will open the "Create Parameter" dialog window, where you'll define its properties.

2. Configure the Parameter's Properties

The dialog box presents several key options that determine how your parameter will behave.

• Name: Give your parameter a clear and descriptive name. This name will appear on the dashboard, so make it easy for users to understand its purpose (e.g., "Select a Date," "Top N Customers," "Sales Growth Percentage").
• Data Type: Choose the type of data your parameter will hold. Tableau offers several options:
• Current value: This is the default value the parameter will be set to when you first show it.
• Allowable values: This critical setting defines what input the user can provide.

3. Show the Parameter Control

Once you click "OK," your new parameter will appear in the Parameters section at the bottom of the Data pane. As mentioned before, a parameter does nothing by itself. To make it visible and interactive on your worksheet or dashboard, right-click the parameter and select Show Parameter.

An interactive control card (a dropdown, slider, or text box) will appear, usually in the top right corner of your worksheet, allowing anyone to change its value.

Putting Your Parameter to Work: Three Practical Examples

Now that you know how to create a parameter, let's bring it to life by connecting it to your visualizations. This is done by referencing the parameter in a calculated field or a filter.

Example 1: Create a Dynamic Top N Filter

Imagine your boss wants to see the top 5 customers by sales, but then the sales director wants to see the top 10, and an analyst wants to see the top 20. Instead of creating three different reports, you can build one with a parameter that lets the user decide.

1. Create the Parameter:
2. Show the Parameter: Right-click on your new parameter and select "Show Parameter" to display the slider.
3. Create a Top N Filter: Drag your "Customer Name" dimension to the Filters shelf. In the dialog that opens, navigate to the "Top" tab. Select "By field," then at the bottom, click the dropdown for the number and choose your [Top N Customers] parameter. Click OK.
4. Build Your View: Drag "Customer Name" to the Rows shelf and "Sales" to the Columns shelf. Now, when you or your users adjust the "Top N Customers" slider, the view will instantly update to show the corresponding number of top customers.

Example 2: Swap Measures in a Single Chart

Consolidate your dashboard by letting users switch which metric they want to see in a chart - for example, toggling between Sales, Profit, and Quantity.

1. Create the Parameter:
2. Create a Calculated Field: We need a calculation that returns the correct measure based on the parameter's selection.

CASE [Select a Measure] WHEN "Sales" THEN SUM([Sales]) WHEN "Profit" THEN SUM([Profit]) WHEN "Quantity" THEN SUM([Quantity]) END

1. Build Your View: Show your "Select a Measure" parameter control. Drag a dimension like "Category" to the Columns shelf and your new [Dynamic Measure] calculated field to the Rows shelf. Now, when you pick a new value from the parameter dropdown, the entire chart updates to show that metric.

Example 3: Simple What-If Analysis

Let's use a parameter to perform a straightforward what-if scenario: what would our total sales be with a user-defined percentage increase?

1. Create the Parameter:
2. Create a Calculated Field:

SUM([Sales]) * (1 + [Sales Growth %])

1. Build Your View: You can display this in multiple ways. A simple way is to create a worksheet with Measure Names on the Rows shelf, and Measure Values on the Text shelf. Add both "Sales" and "Projected Sales" to the Measure Values card. Now, show the "Sales Growth %" parameter. As you move the slider, you’ll see the "Projected Sales" number update in real-time.

Final Thoughts

As you can see, Tableau parameters are incredibly useful for turning a viewer into an active participant. By giving them control over things like what categories to see, what metrics to measure, and what scenarios to explore, you make your data more engaging and unlock deeper insights that a static report could never reveal.

Of course, mastering tools like Tableau takes time, and setting up nested parameters and complex calculated fields can still be a multi-step process. We built Graphed because we believe getting dynamic, interactive reports shouldn't require so much manual work. Instead of learning functions and formulas, you can simply use natural language to ask questions like "Create a dashboard showing how ad spend on Facebook is impacting Shopify sales this month" and get a live, automated report in seconds.