7 Steps to Building a Regression Model in Excel

7 Steps to Building a Regression Model in Excel

Regression analysis helps you understand relationships between variables and make predictions. It explains how one variable (the dependent variable) changes in response to another (the independent variable).

In Excel, you can build regression models easily without any complex coding. In this tutorial, we show 7 steps to building a regression model in Excel.

Assume you’re analyzing how Advertising Budget affects Sales (and possibly other factors like Price and Online Reach).

Step 1: Organizing Your Data

  • Open Excel and input your data in a worksheet. Organize it with independent variables (predictors) in one or more columns and the dependent variable (outcome) in another.
    • Independent variable(s): Advertising, Price
    • Dependent variable: Sales
  • Avoid blank rows or merged cells
  • Ensure numerical columns are formatted correctly

7 Steps to Building a Regression Model in Excel

Step 2: Creating a Scatter Plot

A scatter plot helps visualize the relationship between two variables.

Steps:

  • Select your data.
    • Independent variable (Advertising Spend)
    • Dependent variable (Sales)
  • Go to the Insert tab >> from Charts >> select Scatter >> select Scatter with Smooth Line and Markers

7 Steps to Building a Regression Model in Excel

  • Add titles:
    • Chart title: Advertising Spend vs. Sales
    • X-axis: Advertising Spend
    • Y-axis: Sales
  • You’ll see points showing how Sales respond to Advertising spending

7 Steps to Building a Regression Model in Excel

Interpretation: If the points rise from left to right, there’s a positive correlation (higher advertising → higher sales).

Step 3: Adding a Trendline

To visualize the linear relationship directly:

  • Click on a data point in the scatterplot
  • Choose Add Trendline >> select Linear >> select More Options

7 Steps to Building a Regression Model in Excel

  • Check the boxes for:
    • Display Equation on chart
    • Display R-squared value on chart

7 Steps to Building a Regression Model in Excel

Output:

7 Steps to Building a Regression Model in Excel

y = 2.9697x + 5148.5
R² = 0.9961

Here:

  • y = Sales
  • x = Advertising Spend
  • For every $1,000 increase in advertising, sales increase by about $2,969.70
  • R² = 0.9961 means 99% of the variation in Sales is explained by Advertising Spend

Step 4: Understanding the LINEST Function for the Regression Model

The LINEST function provides detailed regression statistics beyond what a trendline shows. It computes precise coefficients and statistics directly in worksheet cells.

Syntax:

=LINEST(known_y's, known_x's, [const], [stats])

Parameters:

  • known_y’s: Your dependent variable (Sales)
  • known_x’s: Your independent variable(s) (Advertising Spend, etc.)
  • const: TRUE (include intercept) or FALSE
  • stats: TRUE (return full statistics) or FALSE

Use LINEST to:

  • Get precise coefficients for predictions
  • Assess statistical significance
  • Handle multiple predictor variables
  • Calculate standard errors and confidence intervals

Step 5: Running Simple Linear Regression with LINEST

Build a simple linear regression model in Excel using Advertising Spend to predict Sales.

Steps:

  • Select a blank 5-rows × 2-columns range (for example, F2:G6) to capture the full statistics output
  • Enter the following formula
=LINEST(D2:D13, B2:B13, TRUE, TRUE)

Where:

  • D2:D13 → Sales
  • B2:B13 → Advertising

Output (5×2 array): Advertising Spend vs. Sales

7 Steps to Building a Regression Model in Excel

  • Row 1 – Coefficients:
    • Slope: 2.97
    • Intercept: 5148.49
    • Equation:
Sales = 2.97 × Advertising Spend + 5148.49
    • Business insight:
      • For every $1 increase in advertising, sales increase by about $2.97
      • With zero advertising, you’d have base sales of about $5,148.49
      • ROI: Roughly a 3× return on advertising investment (in this sample)
  • Row 2 – Standard errors
    • Slope SE: 0.065
    • Intercept SE: 232.43
    • These are small relative to the coefficients, indicating reliable estimates
  • Row 3 – Model quality
    • R²: 0.996 = 99.6%
    • Standard error of the regression: 297.08
  • Interpretation:
    • Exceptional fit. About 99.6% of sales variation is explained by advertising spend
    • Predictions are typically off by ±$297 (given sales range from roughly $8,000–$21,000)
  • Row 4 – Statistical significance
    • F-statistic: 2060.94 (extremely high)
    • Degrees of freedom: 8
    • The very high F-statistic indicates a highly statistically significant relationship
  • Row 5 – Variance breakdown
    • Regression SS: 181,893,939
    • Residual SS: 706,060

The regression sum of squares is much larger than the residual sum of squares, confirming excellent model fit.

Step 6: Running Multiple Linear Regression with LINEST

Now build a multiple linear regression model using multiple independent variables (Advertising Spend + Price) for better predictions.

Steps:

  • Select a 5-rows × 3-columns cell range (for full statistics output; for example, F2:H6)
  • Enter the following formula
  • If you are using an older version of Excel, press Ctrl + Shift + Enter
=LINEST(D2:D13, B2:C13, TRUE, TRUE)
  • D2:D13 → Sales
  • B2:C13 → Advertising and Price

This model includes both Advertising Spend and Price as predictors.

Output (5×3 array): Advertising + Price vs. Sales

7 Steps to Building a Regression Model in Excel

  • Row 1 – Coefficients appear in REVERSE order (read right to left):
    • Intercept: 19133.73
    • Advertising coefficient: 2.16
    • Price coefficient: -536.15
    • Equation:
Sales = 2.16 × Advertising Spend - 536.15 × Price + 19133.73
    • Business insight:
      • Each $1 in advertising → about $2.16 increase in sales (holding Price constant)
      • Each $1 increase in price → about $536 decrease in sales (holding Advertising constant)
      • Price has a strong negative impact on sales, as expected
  • Row 2 – Standard errors
    • Price SE: 243.30
    • Advertising SE: 0.37
    • Intercept SE: 6349.25
    • Both predictors are reasonably precise (errors are small relative to coefficients)
  • Row 3 – Model quality
    • R²: 0.997 = 99.7%
    • Standard error of the regression: 244.04
    • Interpretation:
      • Slightly better than simple regression (99.7% vs. 99.6%)
      • Adding Price improves the model marginally
      • Prediction error reduced to about ±$244 (from ±$297)
  • Rows 4–5
    • F-statistic: 1529.60 (very high)
    • Degrees of freedom: 7
    • The model is statistically robust

Interpreting the Results

Key Comparisons:

Metric Simple Regression Multiple Regression
99.6% 99.7%
Standard Error $297 $244
Predictors Advertising only Advertising + Price

Business Insights:

  • Both models perform excellently
  • Advertising is highly effective: Strong positive relationship with sales in both models
  • Price matters: The multiple regression shows that each $1 price increase is associated with about a $536 decrease in sales. Adding Price gives slightly better predictions (lower error).
    • Consider pricing strategy carefully
    • Lower prices may boost sales significantly
  • Predictive power: With R² ≈ 99.7%, you can forecast sales very accurately using:
    • Planned advertising budget
    • Intended pricing

7 Steps to Building a Regression Model in Excel

Step 7: Running Regression Using the Data Analysis ToolPak

You can use the Data Analysis ToolPak to get detailed output (coefficients, R², significance). It provides a comprehensive report with detailed statistics.

Enable Data Analysis ToolPak:

  • Go to File >> Options >> Add-ins >> Excel Add-ins >> click Go
  • Check Analysis ToolPak >> click OK

Steps:

  • Go to the Data tab >> select Data Analysis >> select Regression >> click OK

7 Steps to Building a Regression Model in Excel

  • Set Regression:
    • Input Y Range: Select Sales data, including headers (dependent variable)
    • Input X Range: Select Advertising Spend, including headers (or multiple independent variables)
    • Check Labels
    • Choose an Output option: New Worksheet Ply

7 Steps to Building a Regression Model in Excel

Output:

7 Steps to Building a Regression Model in Excel

Interpretation:

  • Intercept: 5148.48
  • Advertising Spend ($): 2.9697
  • R²: 0.9961
  • P-values: Intercept = 1.82E-08, Advertising = 6.12E-11
  • Standard error of the regression: 297.08

Advertising strongly and reliably increases Sales in this dataset, and the linear model explains almost all of the variation.

Both approaches (formula and Data Analysis) fit the same linear model. Coefficients, R², F/df, and (when computed) p-values match.

When to Use LINEST vs. Data Analysis → Regression

Use the LINEST function when:

  • You want live, formula-driven results that recalculate with the data (great for what-if dashboards)
  • You want to reference coefficients in other formulas (predictions, scenarios)
  • You’re comfortable with array outputs and, if needed, computing p-values from t = β/SE

Use Data Analysis → Regression when:

  • You want a readable, one-click report with p-values and confidence intervals shown directly
  • You’re teaching/reporting and need a formatted ANOVA table
  • You don’t need results to update automatically when data change

Bonus: Predicting Future Sales

Once you have your regression equation, you can predict future sales.

Assume you plan to spend $6,000 on advertising and set the price at $17. Predict sales with the multiple regression model.

Using Multiple Regression:

Sales = 2.16 × Advertising Spend - 536.15 × Price + 19133.73
= 2.16 * 6000 - 536.15 * 17 + 19133.73
= 22979.18

Your model predicts approximately $22,979 in sales for this scenario.

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Conclusion

You can follow these 7 steps to build a regression model in Excel. Excel provides essential tools for regression analysis, including scatterplots, Trendlines, the Data Analysis ToolPak, and the LINEST function. With these, you can identify relationships between variables, quantify trends with coefficients, and predict future outcomes. Whether it’s sales forecasting, cost prediction, or performance analysis, regression in Excel is a powerful and accessible method for turning your data into insights.

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