number_format_i18n( float $number, int $decimals = 0 ): string

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$numberfloat

The number to convert based on locale.

$decimalsintoptional

Precision of the number of decimal places. Default 0.Default: 0

Return value

string

Converted number in string format.

Code examples

Every example is editable and runs in a real WordPress booted in your browser by WordPress Playground. Press Run, then edit the code: clicking away re-runs it. Nothing is sent anywhere until you do.

$price = get_post_meta( 2, 'price', true );

if ( '' === $price ) {
	$price = 0;
}

$formatted_price = number_format_i18n( (float) $price, 2 );

echo esc_html( 'Price: ' . $formatted_price );

$post_ids = array( 1, 2, 3, 4, 5 );
$total_comments = 0;

foreach ( $post_ids as $post_id ) {
	$total_comments += (int) get_comments_number( $post_id );
}

$average = $total_comments / count( $post_ids );

echo esc_html( 'Average comments per post: ' . number_format_i18n( $average, 1 ) );

Common problems and fixes · 4

• Why does number_format_i18n give me a period and comma even though my site is in another language?
• Why did my decimal places disappear from the formatted number?
• Can I get number_format_i18n to return a negative number of decimal places or skip rounding entirely?
• How do I change the formatted output site-wide without editing every call?

Alternatives and related functions

number_format

When you don't need locale-aware separators and just want PHP's native rounding and formatting behavior.

size_format

When you're formatting a byte count (like a file or upload size) rather than an arbitrary number.

WP_Locale

When you need the raw decimal_point or thousands_sep strings for the current locale instead of a fully formatted number.

Performance profile

How much work a call to number_format_i18n() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class

Trivial

Touches nothing outside its own arguments.

Scaling

Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions

20–27

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 35.

Plugin surface

1 hook

Third-party callbacks on 'number_format_i18n' run inside this call, and their cost is not bounded by anything here.

Called by

50

50 places in core call this, so the cost is paid more often than your own code shows.

What it touches

• hookthird-party callbacksapply_filters()called directly

What one call costs · 1 distinct outcome

One number would be a lie: the work depends on which branch runs. These are every distinct cost number_format_i18n() can have, taken from its control-flow graph on PHP 8.5.

Hooks and filters fired · 1

One hook fires while number_format_i18n() runs, in this order:

1. 1
   apply_filters( number_format_i18n )filterline 439 (+19 into the body)

   Filters the number formatted based on the locale.

Uses · 2

• absint()Converts a value to non-negative integer.
• apply_filters()Calls the callback functions that have been added to a filter hook.

Used by · 50

• Twenty_Fourteen_Ephemera_Widget::widget()Output the HTML for this widget.
• WP_Comments_List_Table::get_views()
• WP_Customize_Manager::handle_load_themes_request()Loads themes into the theme browsing/installation UI.
• WP_Customize_Manager::save_changeset_post()Saves the post for the loaded changeset.
• WP_Customize_Nav_Menus::customize_register()Adds the customizer settings and controls.
• WP_Customize_Nav_Menus::enqueue_scripts()Enqueues scripts and styles for Customizer pane.
• WP_Customize_Widgets::enqueue_scripts()Enqueues scripts and styles for Customizer panel and export data to JavaScript.
• WP_List_Table::ajax_response()Handles an incoming ajax request (called from admin-ajax.php)
• WP_List_Table::comments_bubble()Displays a comment count bubble.
• WP_List_Table::pagination()Displays the pagination.
• WP_MS_Sites_List_Table::column_users()Handles the users column output.
• WP_MS_Sites_List_Table::get_views()Gets links to filter sites by status.

Source code

View on Trac ↗View on GitHub ↗

420function number_format_i18n( $number, $decimals = 0 ) {421	global $wp_locale;422 423	if ( isset( $wp_locale ) ) {424		$formatted = number_format( $number, absint( $decimals ), $wp_locale->number_format['decimal_point'], $wp_locale->number_format['thousands_sep'] );425	} else {426		$formatted = number_format( $number, absint( $decimals ) );427	}428 429	/**430	 * Filters the number formatted based on the locale.431	 *432	 * @since 2.8.0433	 * @since 4.9.0 The `$number` and `$decimals` parameters were added.434	 *435	 * @param string $formatted Converted number in string format.436	 * @param float  $number    The number to convert based on locale.437	 * @param int    $decimals  Precision of the number of decimal places.438	 */439	return apply_filters( 'number_format_i18n', $formatted, $number, $decimals );440}

Changelog

Introduced in 2.3.0. Unchanged from 6.7.7 through 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data

Generated from the wordpress-develop 6.7.7 tag, from src/wp-includes/functions.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

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