How to get the pixel height of a character in the specified font using the imagefontheight() function in PHP?

The imagefontheight() function is an inbuilt PHP function used to get the pixel height of a character in the specified font. This is particularly useful when working with GD library for dynamic image generation and text positioning.

Syntax

int imagefontheight(int $font)

Parameters

The imagefontheight() function accepts one parameter −

$font − The font identifier. This can be:

• Built-in fonts: Integer values 1, 2, 3, 4, or 5 (predefined font sizes)
• Custom fonts: Font resource loaded using imageloadfont() function

Return Value

Returns the pixel height of the specified font as an integer.

Example 1: Single Font Height

Here's a basic example to get the height of a built-in font −

<?php
    // Get font height for built-in font size 3
    echo 'Font height: ' . imagefontheight(3);
?>

Font height: 13

Example 2: All Built-in Font Heights

This example demonstrates the heights of all built-in fonts −

<?php
    // Get font heights for all built-in fonts (1-5)
    echo 'Font height for font value 1 is: ' . imagefontheight(1) . "<br>";
    echo 'Font height for font value 2 is: ' . imagefontheight(2) . "<br>";
    echo 'Font height for font value 3 is: ' . imagefontheight(3) . "<br>";
    echo 'Font height for font value 4 is: ' . imagefontheight(4) . "<br>";
    echo 'Font height for font value 5 is: ' . imagefontheight(5) . "<br>";
?>

Font height for font value 1 is: 8
Font height for font value 2 is: 13
Font height for font value 3 is: 13
Font height for font value 4 is: 16
Font height for font value 5 is: 15

Font Size Reference

Conclusion

The imagefontheight() function is essential for calculating text positioning and layout in GD image operations. Use it alongside imagefontwidth() for precise text placement in dynamically generated images.