To set the button width, use the CSS width property.
Example
You can try to run the following code to set the width of a button −
<!DOCTYPE html> <html> <head> <style> .btn { background-color: yellow; color: black; width: 120px; text-align: center; font-size: 15px; padding: 20px; border-radius: 15px; border: 3px dashed blue; } </style> </head> <body> <h2>Result</h2> <p>Click below for result:</p> <button class = "btn">Result</button> </body> </html>