diff --git a/apps/files/ajax/delete.php b/apps/files/ajax/delete.php
index 6532b76df2..293543c547 100644
--- a/apps/files/ajax/delete.php
+++ b/apps/files/ajax/delete.php
@@ -21,8 +21,20 @@ foreach($files as $file) {
 	}
 }
 
+// updated max file size after upload
+$l=new OC_L10N('files');
+$maxUploadFilesize=OCP\Util::maxUploadFilesize($dir);
+$maxHumanFilesize=OCP\Util::humanFileSize($maxUploadFilesize);
+$maxHumanFilesize=$l->t('Upload') . ' max. '.$maxHumanFilesize;
+
 if($success) {
-	OCP\JSON::success(array("data" => array( "dir" => $dir, "files" => $files )));
+	OCP\JSON::success(array("data" => array( "dir" => $dir, "files" => $files,
+		'uploadMaxFilesize'=>$maxUploadFilesize,
+		'maxHumanFilesize'=>$maxHumanFilesize
+	)));
 } else {
-	OCP\JSON::error(array("data" => array( "message" => "Could not delete:\n" . $filesWithError )));
+	OCP\JSON::error(array("data" => array( "message" => "Could not delete:\n" . $filesWithError,
+		'uploadMaxFilesize'=>$maxUploadFilesize,
+		'maxHumanFilesize'=>$maxHumanFilesize
+	)));
 }
diff --git a/apps/files/ajax/getstoragestats.php b/apps/files/ajax/getstoragestats.php
new file mode 100644
index 0000000000..e55e346ed6
--- /dev/null
+++ b/apps/files/ajax/getstoragestats.php
@@ -0,0 +1,16 @@
+<?php
+
+// only need filesystem apps
+$RUNTIME_APPTYPES = array('filesystem');
+
+OCP\JSON::checkLoggedIn();
+
+$l=new OC_L10N('files');
+$maxUploadFilesize = OCP\Util::maxUploadFilesize($dir);
+$maxHumanFilesize = OCP\Util::humanFileSize($maxUploadFilesize);
+$maxHumanFilesize = $l->t('Upload') . ' max. ' . $maxHumanFilesize;
+
+// send back json
+OCP\JSON::success(array('data' => array('uploadMaxFilesize' => $maxUploadFilesize,
+										'maxHumanFilesize'  => $maxHumanFilesize
+)));
diff --git a/apps/files/ajax/upload.php b/apps/files/ajax/upload.php
index 2a2d935da6..9339801960 100644
--- a/apps/files/ajax/upload.php
+++ b/apps/files/ajax/upload.php
@@ -10,8 +10,17 @@ OCP\JSON::checkLoggedIn();
 OCP\JSON::callCheck();
 $l=OC_L10N::get('files');
 
+// current max upload size
+$l=new OC_L10N('files');
+$maxUploadFilesize=OCP\Util::maxUploadFilesize($dir);
+$maxHumanFilesize=OCP\Util::humanFileSize($maxUploadFilesize);
+$maxHumanFilesize=$l->t('Upload') . ' max. '.$maxHumanFilesize;
+
 if (!isset($_FILES['files'])) {
-	OCP\JSON::error(array('data' => array( 'message' => $l->t( 'No file was uploaded. Unknown error' ))));
+	OCP\JSON::error(array('data' => array( 'message' => $l->t( 'No file was uploaded. Unknown error' ),
+		'uploadMaxFilesize'=>$maxUploadFilesize,
+		'maxHumanFilesize'=>$maxHumanFilesize
+	)));
 	exit();
 }
 
@@ -28,7 +37,10 @@ foreach ($_FILES['files']['error'] as $error) {
 			UPLOAD_ERR_NO_TMP_DIR=>$l->t('Missing a temporary folder'),
 			UPLOAD_ERR_CANT_WRITE=>$l->t('Failed to write to disk'),
 		);
-		OCP\JSON::error(array('data' => array( 'message' => $errors[$error] )));
+		OCP\JSON::error(array('data' => array( 'message' => $errors[$error],
+			'uploadMaxFilesize'=>$maxUploadFilesize,
+			'maxHumanFilesize'=>$maxHumanFilesize
+		)));
 		exit();
 	}
 }
@@ -42,7 +54,9 @@ foreach($files['size'] as $size) {
 	$totalSize+=$size;
 }
 if($totalSize>OC_Filesystem::free_space($dir)) {
-	OCP\JSON::error(array('data' => array( 'message' => $l->t( 'Not enough space available' ))));
+	OCP\JSON::error(array('data' => array( 'message' => $l->t( 'Not enough space available' ),
+		'uploadMaxFilesize'=>$maxUploadFilesize,
+		'maxHumanFilesize'=>$maxHumanFilesize)));
 	exit();
 }
 
@@ -56,11 +70,19 @@ if(strpos($dir, '..') === false) {
 		if(is_uploaded_file($files['tmp_name'][$i]) and OC_Filesystem::fromTmpFile($files['tmp_name'][$i], $target)) {
 			$meta = OC_FileCache::get($target);
 			$id = OC_FileCache::getId($target);
+			// updated max file size after upload
+			$maxUploadFilesize=OCP\Util::maxUploadFilesize($dir);
+			$maxHumanFilesize=OCP\Util::humanFileSize($maxUploadFilesize);
+			$maxHumanFilesize=$l->t('Upload') . ' max. '.$maxHumanFilesize;
+
 			$result[]=array( 'status' => 'success',
 				'mime'=>$meta['mimetype'],
 				'size'=>$meta['size'],
 				'id'=>$id,
-				'name'=>basename($target));
+				'name'=>basename($target),
+				'uploadMaxFilesize'=>$maxUploadFilesize,
+				'maxHumanFilesize'=>$maxHumanFilesize
+			);
 		}
 	}
 	OCP\JSON::encodedPrint($result);
@@ -69,4 +91,7 @@ if(strpos($dir, '..') === false) {
 	$error=$l->t( 'Invalid directory.' );
 }
 
-OCP\JSON::error(array('data' => array('message' => $error )));
+OCP\JSON::error(array('data' => array('message' => $error,
+	'uploadMaxFilesize'=>$maxUploadFilesize,
+	'maxHumanFilesize'=>$maxHumanFilesize
+)));
diff --git a/apps/files/index.php b/apps/files/index.php
index 08193eaee7..1c4b7fbd49 100644
--- a/apps/files/index.php
+++ b/apps/files/index.php
@@ -28,6 +28,7 @@ OCP\User::checkLoggedIn();
 OCP\Util::addStyle('files', 'files');
 OCP\Util::addscript('files', 'jquery.iframe-transport');
 OCP\Util::addscript('files', 'jquery.fileupload');
+OCP\Util::addscript('files', 'jquery-visibility');
 OCP\Util::addscript('files', 'files');
 OCP\Util::addscript('files', 'filelist');
 OCP\Util::addscript('files', 'fileactions');
@@ -79,13 +80,7 @@ $breadcrumbNav = new OCP\Template('files', 'part.breadcrumb', '');
 $breadcrumbNav->assign('breadcrumb', $breadcrumb, false);
 $breadcrumbNav->assign('baseURL', OCP\Util::linkTo('files', 'index.php') . '?dir=', false);
 
-$upload_max_filesize = OCP\Util::computerFileSize(ini_get('upload_max_filesize'));
-$post_max_size = OCP\Util::computerFileSize(ini_get('post_max_size'));
-$maxUploadFilesize = min($upload_max_filesize, $post_max_size);
-
-$freeSpace = OC_Filesystem::free_space($dir);
-$freeSpace = max($freeSpace, 0);
-$maxUploadFilesize = min($maxUploadFilesize, $freeSpace);
+$maxUploadFilesize=OCP\Util::maxUploadFilesize($dir);
 
 $permissions = OCP\PERMISSION_READ;
 if (OC_Filesystem::isUpdatable($dir . '/')) {
diff --git a/apps/files/js/files.js b/apps/files/js/files.js
index 3a4af6416e..0488062dbc 100644
--- a/apps/files/js/files.js
+++ b/apps/files/js/files.js
@@ -26,6 +26,23 @@ Files={
 		});
 		procesSelection();
 	},
+	updateMaxUploadFilesize:function(response) {
+		if(response == undefined) {
+			return;
+		}
+		if(response.data !== undefined && response.data.uploadMaxFilesize !== undefined) {
+			$('#max_upload').val(response.data.uploadMaxFilesize);
+			$('#data-upload-form a').attr('original-title', response.data.maxHumanFilesize);
+		}
+		if(response[0] == undefined) {
+			return;
+		}
+		if(response[0].uploadMaxFilesize !== undefined) {
+			$('#max_upload').val(response[0].uploadMaxFilesize);
+			$('#data-upload-form a').attr('original-title', response[0].maxHumanFilesize);
+		}
+
+	},
 	isFileNameValid:function (name) {
 		if (name === '.') {
 			$('#notification').text(t('files', '\'.\' is an invalid file name.'));
@@ -317,6 +334,7 @@ $(document).ready(function() {
 												$('#notification').text(t('files', response.data.message));
 												$('#notification').fadeIn();
 											}
+											Files.updateMaxUploadFilesize(response);
 											var file=response[0];
 											// TODO: this doesn't work if the file name has been changed server side
 											delete uploadingFiles[dirName][file.name];
@@ -369,6 +387,8 @@ $(document).ready(function() {
 										.success(function(result, textStatus, jqXHR) {
 											var response;
 											response=jQuery.parseJSON(result);
+											Files.updateMaxUploadFilesize(response);
+
 											if(response[0] != undefined && response[0].status == 'success') {
 												var file=response[0];
 												delete uploadingFiles[file.name];
@@ -402,6 +422,7 @@ $(document).ready(function() {
 						data.submit().success(function(data, status) {
 							// in safari data is a string
 							response = jQuery.parseJSON(typeof data === 'string' ? data : data[0].body.innerText);
+							Files.updateMaxUploadFilesize(response);
 							if(response[0] != undefined && response[0].status == 'success') {
 								var file=response[0];
 								delete uploadingFiles[file.name];
@@ -712,6 +733,32 @@ $(document).ready(function() {
 	});
 
 	resizeBreadcrumbs(true);
+
+	// file space size sync
+	function update_storage_statistics() {
+		$.getJSON(OC.filePath('files','ajax','getstoragestats.php'),function(response) {
+			Files.updateMaxUploadFilesize(response);
+		});
+	}
+
+	// start on load - we ask the server every 5 minutes
+	var update_storage_statistics_interval = 5*60*1000;
+	var update_storage_statistics_interval_id = setInterval(update_storage_statistics, update_storage_statistics_interval);
+
+	// Use jquery-visibility to de-/re-activate file stats sync
+	if ($.support.pageVisibility) {
+		$(document).on({
+			'show.visibility': function() {
+				if (!update_storage_statistics_interval_id) {
+					update_storage_statistics_interval_id = setInterval(update_storage_statistics, update_storage_statistics_interval);
+				}
+			},
+			'hide.visibility': function() {
+				clearInterval(update_storage_statistics_interval_id);
+				update_storage_statistics_interval_id = 0;
+			}
+		});
+	}
 });
 
 function scanFiles(force,dir){
@@ -741,6 +788,7 @@ scanFiles.scanning=false;
 
 function boolOperationFinished(data, callback) {
 	result = jQuery.parseJSON(data.responseText);
+	Files.updateMaxUploadFilesize(result);
 	if(result.status == 'success'){
 		callback.call();
 	} else {
diff --git a/apps/files/js/jquery-visibility.js b/apps/files/js/jquery-visibility.js
new file mode 100644
index 0000000000..a824bf6873
--- /dev/null
+++ b/apps/files/js/jquery-visibility.js
@@ -0,0 +1,32 @@
+/*! http://mths.be/visibility v1.0.5 by @mathias */
+(function (window, document, $, undefined) {
+
+	var prefix,
+		property,
+// In Opera, `'onfocusin' in document == true`, hence the extra `hasFocus` check to detect IE-like behavior
+		eventName = 'onfocusin' in document && 'hasFocus' in document ? 'focusin focusout' : 'focus blur',
+		prefixes = ['', 'moz', 'ms', 'o', 'webkit'],
+		$support = $.support,
+		$event = $.event;
+
+	while ((property = prefix = prefixes.pop()) != undefined) {
+		property = (prefix ? prefix + 'H' : 'h') + 'idden';
+		if ($support.pageVisibility = typeof document[property] == 'boolean') {
+			eventName = prefix + 'visibilitychange';
+			break;
+		}
+	}
+
+	$(/blur$/.test(eventName) ? window : document).on(eventName, function (event) {
+		var type = event.type,
+			originalEvent = event.originalEvent,
+			toElement = originalEvent.toElement;
+// If it’s a `{focusin,focusout}` event (IE), `fromElement` and `toElement` should both be `null` or `undefined`;
+// else, the page visibility hasn’t changed, but the user just clicked somewhere in the doc.
+// In IE9, we need to check the `relatedTarget` property instead.
+		if (!/^focus./.test(type) || (toElement == undefined && originalEvent.fromElement == undefined && originalEvent.relatedTarget == undefined)) {
+			$event.trigger((property && document[property] || /^(?:blur|focusout)$/.test(type) ? 'hide' : 'show') + '.visibility');
+		}
+	});
+
+}(this, document, jQuery));
diff --git a/lib/helper.php b/lib/helper.php
index 5d7e3fa489..7be54cacbe 100644
--- a/lib/helper.php
+++ b/lib/helper.php
@@ -679,8 +679,8 @@ class OC_Helper {
 		$start = intval($start);
 		$length = intval($length);
 		$string = mb_substr($string, 0, $start, $encoding) .
-		          $replacement .
-		          mb_substr($string, $start+$length, mb_strlen($string, 'UTF-8')-$start, $encoding);
+			$replacement .
+			mb_substr($string, $start+$length, mb_strlen($string, 'UTF-8')-$start, $encoding);
 
 		return $string;
 	}
@@ -748,6 +748,23 @@ class OC_Helper {
 		return $str;
 	}
 
+	/**
+	 * @brief calculates the maximum upload size respecting system settings, free space and user quota
+	 *
+	 * @param $dir the current folder where the user currently operates
+	 * @return number of bytes representing
+	 */
+	public static function maxUploadFilesize($dir) {
+		$upload_max_filesize = OCP\Util::computerFileSize(ini_get('upload_max_filesize'));
+		$post_max_size = OCP\Util::computerFileSize(ini_get('post_max_size'));
+		$maxUploadFilesize = min($upload_max_filesize, $post_max_size);
+
+		$freeSpace = OC_Filesystem::free_space($dir);
+		$freeSpace = max($freeSpace, 0);
+
+		return min($maxUploadFilesize, $freeSpace);
+	}
+
 	/**
 	 * Checks if a function is available
 	 * @param string $function_name
diff --git a/lib/public/util.php b/lib/public/util.php
index 8197482c0d..413dbcccd2 100644
--- a/lib/public/util.php
+++ b/lib/public/util.php
@@ -367,4 +367,14 @@ class Util {
 	public static function recursiveArraySearch($haystack, $needle, $index = null) {
 		return(\OC_Helper::recursiveArraySearch($haystack, $needle, $index));
 	}
+
+	/**
+	 * @brief calculates the maximum upload size respecting system settings, free space and user quota
+	 *
+	 * @param $dir the current folder where the user currently operates
+	 * @return number of bytes representing
+	 */
+	public static function maxUploadFilesize($dir) {
+		return \OC_Helper::maxUploadFilesize($dir);
+	}
 }