What are the potential pitfalls of trying to calculate text width in PHP?

Calculating text width in PHP can be challenging due to variations in font sizes, styles, and rendering across different environments. One potential pitfall is that the calculated width may not accurately reflect the actual width when rendered on a webpage. To address this issue, using PHP's GD library to create an image with the text and then measuring the image's width can provide a more accurate result.

$text = "Lorem ipsum dolor sit amet";
$font = 4; // font size
$width = imagefontwidth($font) * strlen($text);

echo "Text width: " . $width;