Intervention/image · error · RuntimeException

Division by zero

Error message

Division by zero

What it means

Size::aspectRatio() returns width / height as a float. A Size with height 0 is legal (the constructor only forbids negative values), but dividing by that height raises PHP's DivisionByZeroError, which the method catches and rethrows as a library RuntimeException with the message 'Division by zero'. This gives callers a predictable, driver-independent exception for zero-height images.

Source

Thrown at src/Size.php:242

        return new Point(
            $this->pivot()->x() - $size->pivot()->x(),
            $this->pivot()->y() - $size->pivot()->y(),
        );
    }

    /**
     * {@inheritdoc}
     *
     * @see SizeInterface::aspectRatio()
     *
     * @throws RuntimeException
     */
    public function aspectRatio(): float
    {
        try {
            return $this->width() / $this->height();
        } catch (DivisionByZeroError) {
            throw new RuntimeException('Division by zero');
        }
    }

    /**
     * {@inheritdoc}
     *
     * @see SizeInterface::fitsWithin()
     */
    public function fitsWithin(SizeInterface $size): bool
    {
        if ($this->width() > $size->width()) {
            return false;
        }

        if ($this->height() > $size->height()) {
            return false;
        }

View on GitHub (pinned to 5598b9e397)

Solutions

1. Guard before dividing: if ($size->height() === 0) handle the degenerate case instead of calling aspectRatio()
2. Fix the upstream code that produced a zero-height Size
3. Treat zero-height images as invalid input and reject them early in your pipeline

Example fix

// before
$ratio = $image->size()->aspectRatio(); // RuntimeException when height is 0

// after
$size = $image->size();
$ratio = $size->height() > 0 ? $size->aspectRatio() : null;
if ($ratio === null) {
    // handle degenerate image
}

// Guard zero-height sizes before computing the ratio
$size = $image->size();

if ($size->height() === 0) {
    throw new \RuntimeException('Image has zero height; aspect ratio undefined');
}

$ratio = $size->aspectRatio();

function hasDefinedAspectRatio(\Intervention\Image\Interfaces\SizeInterface $size): bool
{
    return $size->height() !== 0;
}

use Intervention\Image\Exceptions\RuntimeException;

try {
    $ratio = $size->aspectRatio();
} catch (RuntimeException $e) {
    // message: 'Division by zero'
    $ratio = null; // degenerate zero-height image
}

When it happens

Trigger: Calling (new Size(120, 0))->aspectRatio(), or $image->size()->aspectRatio() on a degenerate zero-height image/crop result. Also reachable indirectly through proportional sizing math that divides by a zero height.

Common situations: Edge-crop results that produce a zero-height region; test fixtures using 0-height canvases; images or crops created from bad user dimensions that passed the >= 0 constructor check; analytics code computing aspect ratios for arbitrary stored sizes.

Related errors

• Width of {class} must be greater than or equal to 0
• Height of {class} must be greater than or equal to 0
• Invalid target size {width}x{height}
• Unable to set array key, use setWidth() or setHeight()
• Unable to unset array key

AI-assisted analysis of Intervention/image@5598b9e397 (2026-08-23). Data as JSON: /api/errors/5f729a38ab28aa74. Report an issue: GitHub.