diff --git a/wp-admin/includes/upload.php b/wp-admin/includes/upload.php
index 2dd7cb0f34..b09ff2fdff 100644
--- a/wp-admin/includes/upload.php
+++ b/wp-admin/includes/upload.php
@@ -5,8 +5,9 @@ function wp_upload_display( $dims = false, $href = '' ) {
 	$id = get_the_ID();
 	$attachment_data = wp_get_attachment_metadata( $id );
 	$is_image = (int) wp_attachment_is_image();
+	$filesystem_path = get_attached_file( $id );
 	if ( !isset($attachment_data['width']) && $is_image ) {
-		if ( $image_data = getimagesize( get_attached_file( $id ) ) ) {
+		if ( $image_data = getimagesize( $filesystem_path ) ) {
 			$attachment_data['width'] = $image_data[0];
 			$attachment_data['height'] = $image_data[1];
 			wp_update_attachment_metadata( $id, $attachment_data );
@@ -38,6 +39,7 @@ function wp_upload_display( $dims = false, $href = '' ) {
 		$r .= "\t\t\t$innerHTML";
 	if ( $href )
 		$r .= "</a>\n";
+	$r .= "\t\t\t\t<span class='upload-file-size'>".size_format(filesize($filesystem_path))."</span>\n";
 	$r .= "\n\t\t<div class='upload-file-data'>\n\t\t\t<p>\n";
 	$r .= "\t\t\t\t<input type='hidden' name='attachment-url-$id' id='attachment-url-$id' value='$src' />\n";
 	$r .= "\t\t\t\t<input type='hidden' name='attachment-url-base-$id' id='attachment-url-base-$id' value='$src_base' />\n";
diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index 0484b8794b..21b917a3d5 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -91,6 +91,22 @@ function number_format_i18n($number, $decimals = null) {
 	return number_format($number, $decimals, $wp_locale->number_format['decimal_point'], $wp_locale->number_format['thousands_sep']);
 }
 
+function size_format($bytes, $decimals = null) {
+	// technically the correct unit names for powers of 1024 are KiB, MiB etc
+	// see http://en.wikipedia.org/wiki/Byte
+	$quant = array(
+		'TB' => pow(1024, 4),
+		'GB' => pow(1024, 3),
+		'MB' => pow(1024, 2),
+		'kB' => pow(1024, 1),
+		'B'  => pow(1024, 0),
+	);
+
+	foreach ($quant as $unit => $mag)
+		if ( intval($bytes) >= $mag )
+			return number_format_i18n($bytes / $mag, $decimals) . ' ' . $unit;
+}
+
 function get_weekstartend($mysqlstring, $start_of_week) {
 	$my = substr($mysqlstring,0,4);
 	$mm = substr($mysqlstring,8,2);