diff --git a/octoprint_psucontrol/__init__.py b/octoprint_psucontrol/__init__.py
index 887648c..5082c5c 100644
--- a/octoprint_psucontrol/__init__.py
+++ b/octoprint_psucontrol/__init__.py
@@ -8,6 +8,7 @@
 import octoprint.plugin
 from octoprint.server import user_permission
 from octoprint.events import Events
+from octoprint.util import RepeatedTimer
 import time
 import subprocess
 import threading
@@ -103,6 +104,7 @@ def __init__(self):
         self.autoOnTriggerGCodeCommands = ''
         self._autoOnTriggerGCodeCommandsArray = []
         self.enablePowerOffWarningDialog = True
+        self.enableIdleCountdownTimer = True
         self.powerOffWhenIdle = False
         self.idleTimeout = 0
         self.idleIgnoreCommands = ''
@@ -120,6 +122,9 @@ def __init__(self):
         self._check_psu_state_thread = None
         self._check_psu_state_event= threading.Event()
         self._idleTimer = None
+        self._idleCountdown = None
+        self._idleStartTime = 0
+        self._idleTimeLeft = None
         self._waitForHeaters = False
         self._skipIdleTimer = False
         self._configuredGPIOPins = []
@@ -200,6 +205,9 @@ def on_settings_initialized(self):
         self.enablePowerOffWarningDialog = self._settings.get_boolean(["enablePowerOffWarningDialog"])
         self._logger.debug("enablePowerOffWarningDialog: %s" % self.enablePowerOffWarningDialog)
 
+        self.enableIdleCountdownTimer = self._settings.get_boolean(["enableIdleCountdownTimer"])
+        self._logger.debug("enableIdleCountdownTimer: %s" % self.enableIdleCountdownTimer)
+
         self.powerOffWhenIdle = self._settings.get_boolean(["powerOffWhenIdle"])
         self._logger.debug("powerOffWhenIdle: %s" % self.powerOffWhenIdle)
 
@@ -393,22 +401,40 @@ def _check_psu_state(self):
             self._check_psu_state_event.wait(self.sensePollingInterval)
             self._check_psu_state_event.clear()
 
+    def _set_start_time(self):
+        self._idleStartTime = time.time()
+
+    def _refresh_countdown(self):
+        if self._idleStartTime == 0 or not self.powerOffWhenIdle or not self.enableIdleCountdownTimer or self._printer.is_printing() or self._printer.is_paused():
+            self.idleTimeLeft = None
+        else:
+            self.idleTimeLeft = time.strftime("%-M:%S", time.gmtime((self.idleTimeout * 60) - (time.time() - self._idleStartTime)))
+        self._plugin_manager.send_plugin_message(self._identifier, dict(idleTimeLeft=self.idleTimeLeft))
+
     def _start_idle_timer(self):
         self._stop_idle_timer()
         
         if self.powerOffWhenIdle and self.isPSUOn:
             self._idleTimer = ResettableTimer(self.idleTimeout * 60, self._idle_poweroff)
+            self._idleCountdown = RepeatedTimer(1.0, self._refresh_countdown)
             self._idleTimer.start()
+            self._set_start_time()
+            self._idleCountdown.start()
 
     def _stop_idle_timer(self):
         if self._idleTimer:
             self._idleTimer.cancel()
             self._idleTimer = None
+            self._idleStartTime = 0
+            self._idleCountdown.cancel()
+            self._idleCountdown = None
+            self._refresh_countdown()
 
     def _reset_idle_timer(self):
         try:
             if self._idleTimer.is_alive():
                 self._idleTimer.reset()
+                self._set_start_time()
             else:
                 raise Exception()
         except:
@@ -663,6 +689,7 @@ def get_settings_defaults(self):
             autoOn = False,
             autoOnTriggerGCodeCommands = "G0,G1,G2,G3,G10,G11,G28,G29,G32,M104,M106,M109,M140,M190",
             enablePowerOffWarningDialog = True,
+            enableIdleCountdownTimer = True,
             powerOffWhenIdle = False,
             idleTimeout = 30,
             idleIgnoreCommands = 'M105',
@@ -707,6 +734,7 @@ def on_settings_save(self, data):
         self.idleTimeout = self._settings.get_int(["idleTimeout"])
         self.idleIgnoreCommands = self._settings.get(["idleIgnoreCommands"])
         self.enablePowerOffWarningDialog = self._settings.get_boolean(["enablePowerOffWarningDialog"])
+        self.enableIdleCountdownTimer = self._settings.get_boolean(["enableIdleCountdownTimer"])
         self._idleIgnoreCommandsArray = self.idleIgnoreCommands.split(',')
         self.idleTimeoutWaitTemp = self._settings.get_int(["idleTimeoutWaitTemp"])
 
diff --git a/octoprint_psucontrol/static/js/psucontrol.js b/octoprint_psucontrol/static/js/psucontrol.js
index e98bb85..2a65c05 100644
--- a/octoprint_psucontrol/static/js/psucontrol.js
+++ b/octoprint_psucontrol/static/js/psucontrol.js
@@ -4,13 +4,14 @@ $(function() {
 
         self.settingsViewModel = parameters[0]
         self.loginState = parameters[1];
-        
+
         self.settings = undefined;
         self.scripts_gcode_psucontrol_post_on = ko.observable(undefined);
         self.scripts_gcode_psucontrol_pre_off = ko.observable(undefined);
 
         self.hasGPIO = ko.observable(true);
         self.isPSUOn = ko.observable(undefined);
+        self.idleTimeLeft = ko.observable(undefined);
 
         self.psu_indicator = $("#psucontrol_indicator");
 
@@ -78,6 +79,10 @@ $(function() {
             if (data.isPSUOn !== undefined) {
                 self.isPSUOn(data.isPSUOn);
             }
+
+            if (data.idleTimeLeft !== undefined) {
+                self.idleTimeLeft(data.idleTimeLeft);
+            }
         };
 
         self.togglePSU = function() {
diff --git a/octoprint_psucontrol/templates/psucontrol_navbar.jinja2 b/octoprint_psucontrol/templates/psucontrol_navbar.jinja2
index f4b574a..374ef47 100644
--- a/octoprint_psucontrol/templates/psucontrol_navbar.jinja2
+++ b/octoprint_psucontrol/templates/psucontrol_navbar.jinja2
@@ -1,3 +1,4 @@
 <a id="psucontrol_indicator" class="pull-right" title="Toggle PSU" href="#" data-bind="click: function() { loginState.isUser() && $root.togglePSU(); }, visible: (isPSUOn() !== undefined)" style="display: none">
     <i class="icon-bolt"></i>
+    <span data-bind="attr: { title: 'Idle Countdown' }, html: idleTimeLeft()"></span>
 </a>
diff --git a/octoprint_psucontrol/templates/psucontrol_settings.jinja2 b/octoprint_psucontrol/templates/psucontrol_settings.jinja2
index 0c06c18..8718e88 100644
--- a/octoprint_psucontrol/templates/psucontrol_settings.jinja2
+++ b/octoprint_psucontrol/templates/psucontrol_settings.jinja2
@@ -5,6 +5,9 @@
             <label class="checkbox">
             <input type="checkbox" data-bind="checked: settings.plugins.psucontrol.enablePowerOffWarningDialog"> Show warning dialog when powering off via toggle button.
             </label>
+            <label class="checkbox">
+            <input type="checkbox" data-bind="checked: settings.plugins.psucontrol.enableIdleCountdownTimer"> Show idle countdown timer in the navbar.
+            </label>
         </div>
     </div>
     <!-- ko if: hasGPIO() && (settings.plugins.psucontrol.switchingMethod() === "GPIO" || settings.plugins.psucontrol.sensingMethod() === "GPIO") -->