The Basic Steps to Knit Your R Markdown File to Word
To knit an R Markdown file to Word in RStudio, you need a YAML header that tells RStudio which output format to use, then click the Knit button. The YAML header is the section at the very top of your file, between the three dashes. Change the output line from html_document to word_document, save the file, and click Knit. RStudio will create a .docx file in the same folder as your .Rmd file.
If you do not have a YAML header yet, add one at the top of your file before any other content. The minimum header looks like this:
--- title: "Your Document Title" output: word_document ---
After you save the file with a .Rmd extension, the Knit button will appear in the toolbar at the top of the editor. Click it, and RStudio will run all your code chunks, combine the results with your text, and save the Word file automatically.
Key Takeaways
- Your R Markdown file must have a YAML header at the top with output: word_document to knit to Word format.
- Click the Knit button in the RStudio toolbar to generate the Word file; RStudio saves it in the same folder as your .Rmd file.
- Code chunks run automatically during knitting, so your Word document will include both your code results and your text.
- You can customize the Word output by adding options like toc: true for a table of contents or number_sections: true for numbered headings.
Setting Up Your YAML Header for Word Output
The YAML header controls how your document looks and behaves. For a basic Word document, you only need the three lines shown above. However, you can add more options to customize the output.
Common options include toc: true to add a table of contents, toc_depth: 2 to control how many heading levels appear in the table of contents, and number_sections: true to automatically number your sections. Here is an example with these options:
--- title: "My Analysis" author: "Your Name" date: "`r Sys.Date()`" output: word_document: toc: true toc_depth: 2 number_sections: true ---
Notice that when you add options, word_document becomes word_document: with a colon, and the options go on the lines below, indented with spaces (not tabs). RStudio will show an error if the indentation is wrong, so check the error message if knitting fails.
Controlling Code Visibility in Your Word Document
By default, RStudio includes both your code and its output in the Word file. If you want to hide the code and show only the results, add echo: false to your code chunk header. For example, a chunk that hides code looks like this:
```{r, echo: false} summary(mtcars) ```
You can also hide the output and show only the code by using eval: false, or hide both code and output with include: false. If you want to hide all code chunks throughout the entire document, add this line to your YAML header under the word_document options:
echo: false
Another useful option is message: false and warning: false, which prevent R messages and warnings from appearing in your Word document. These keep your output clean when you load packages or run code that produces non-critical messages.
Troubleshooting Common Knitting Problems
If the Knit button does not appear, your file is not saved as .Rmd. Save it with that extension and the button will show up. If knitting starts but fails partway through, check the console at the bottom of RStudio for the error message — usually it points to a specific line number where the code broke.
YAML indentation errors are the most common cause of failure. RStudio is strict about spaces: use two spaces per indent level, never tabs. If you copy a YAML header from a website, the spaces may not paste correctly, so retype them by hand or check the raw text.
If a code chunk runs fine in the console but fails during knitting, the problem is usually that the chunk depends on something you loaded earlier in the console but did not load in the document itself. Make sure all library() calls and data imports happen inside code chunks, not just in the console.
If Word is already open with the file you are trying to knit, RStudio may not be able to overwrite it. Close the Word file first, then knit again.
Adding Formatting and Styles to Your Word Document
R Markdown creates a plain Word document with basic formatting. You can add bold text with **text**, italics with *text*, and headings with #, ##, and ###. These will carry over to the Word file with standard formatting.
If you want more control over the appearance — custom fonts, colors, margins, or specific styles — you can use a reference document. Create a Word file with the styles and formatting you want, then tell RStudio to use it as a template. Add this to your YAML header:
reference_docx: "template.docx"
RStudio will explore the styles from template.docx to your knitted document. This is useful when you need to match a company template or follow specific formatting rules.
Working with Tables and Images in Word Output
Tables created by R code will appear in your Word document as actual tables, not as plain text. If you use the knitr::kable() function, your table will format cleanly. For example:
```{r} knitr::kable(head(mtcars)) ```
Images generated by code chunks will also embed directly in the Word file. If you want to include an image file from your computer, use the markdown syntax: . The image will appear in the Word document at that location.
You can control image size by adding width and height options to the code chunk header. For example, {r, fig.width=6, fig.height=4} sets the figure to 6 inches wide and 4 inches tall in the final document.
Frequently Asked Questions
What is the difference between knitting to Word and knitting to HTML?
Word output creates a .docx file you can open, edit, and share with people who use Microsoft Word. HTML creates a web page. Word is better when you need a document people can print or edit further; HTML is better when you want to share results online or need interactive features.
Can I knit to Word if I do not have Microsoft Word installed?
Yes. RStudio creates the Word file itself; you do not need Word installed. You can open and edit the .docx file with free tools like LibreOffice or Google Docs. However, some advanced formatting may not display the same way in other programs.
Why does my code chunk produce an error during knitting but works fine in the console?
The knitting environment is separate from your console. If you loaded data or packages in the console but not in a code chunk, the chunk will not have access to them. Make sure all setup code — library calls, data imports, and variable definitions — happens inside code chunks in your document.
How do I add a page break in my Word document?
Use the markdown syntax \newpage on its own line to insert a page break. This works in R Markdown files knitted to Word and will create a new page at that location in your document.
Can I use R code to generate the YAML header automatically?
No, the YAML header must be written as plain text at the top of your file. However, you can create an R Markdown template in RStudio with your preferred YAML settings, then use that template for new files. Go to File > New File > R Markdown and choose a template.