diff --git a/modoboa/admin/models/domain.py b/modoboa/admin/models/domain.py
index 516378605..50a04d97b 100644
--- a/modoboa/admin/models/domain.py
+++ b/modoboa/admin/models/domain.py
@@ -163,8 +163,8 @@ class Domain(AdminObject):
             return "success"
 
     @cached_property
-    def quota_usage(self):
-        """Return current quota usage."""
+    def allocated_quota(self):
+        """Return current quota allocation."""
         if not self.quota:
             return 0
         if not self.mailbox_set.exists():
@@ -173,11 +173,11 @@ class Domain(AdminObject):
             total=models.Sum("quota"))["total"]
 
     @cached_property
-    def quota_usage_in_percent(self):
-        """Return quota usage in percent."""
-        if not self.quota_usage:
+    def allocated_quota_in_percent(self):
+        """Return allocated quota in percent."""
+        if not self.allocated_quota:
             return 0
-        return int(self.quota_usage / float(self.quota) * 100)
+        return int(self.allocated_quota / float(self.quota) * 100)
 
     def add_admin(self, account):
         """Add a new administrator to this domain.
diff --git a/modoboa/admin/models/mailbox.py b/modoboa/admin/models/mailbox.py
index bd50a3363..a7e7eb0d6 100644
--- a/modoboa/admin/models/mailbox.py
+++ b/modoboa/admin/models/mailbox.py
@@ -24,6 +24,17 @@ from .base import AdminObject
 from .domain import Domain
 
 
+class QuotaManager(models.Manager):
+    """Custom manager for Quota."""
+
+    def get_domain_usage(self, domain):
+        """Return current usage for domain."""
+        qset = self.get_queryset().filter(
+            username__endswith="@{}".format(domain.name))
+        result = qset.aggregate(usage=models.Sum("bytes"))
+        return result.get("usage", 0)
+
+
 class Quota(models.Model):
 
     """Keeps track of Mailbox current quota."""
@@ -32,6 +43,8 @@ class Quota(models.Model):
     bytes = models.BigIntegerField(default=0)
     messages = models.IntegerField(default=0)
 
+    objects = QuotaManager()
+
     class Meta:
         app_label = "admin"
 
@@ -242,7 +255,7 @@ class Mailbox(AdminObject):
             if self.domain.quota and not override_rules:
                 raise lib_exceptions.BadRequest(_("A quota is required"))
         elif self.domain.quota:
-            quota_usage = self.domain.quota_usage
+            quota_usage = self.domain.allocated_quota
             if old_quota:
                 quota_usage -= old_quota
             if quota_usage + self.quota > self.domain.quota:
diff --git a/modoboa/admin/templates/admin/domain_detail.html b/modoboa/admin/templates/admin/domain_detail.html
index fbe3db7b4..06d8643e7 100644
--- a/modoboa/admin/templates/admin/domain_detail.html
+++ b/modoboa/admin/templates/admin/domain_detail.html
@@ -60,8 +60,13 @@
         {% if domain.quota %}
           <tr>
             <th>{% trans "Usage" %}</a></th>
-            <td>{% include "common/progressbar.html" with id="quotabar" value=domain.quota_usage_in_percent %}</td>
-        </tr>
+            <td>
+              <div class="progress">
+                <div class="{% progress_color used_quota_in_percent %}" style="width: {{ used_quota_in_percent }}%" title="{{ used_quota_in_percent }}% ({{ used_quota }} {% trans "MB" %}) {% trans 'used' context 'quota' %}"></div>
+                <div class="{% progress_color domain.allocated_quota_in_percent %}" style="width: {{ allocated_quota }}%" title="{{ domain.allocated_quota_in_percent }}% ({{ domain.allocated_quota }} {% trans "MB" %}) {% trans 'allocated' %}"></div>
+              </div>
+            </td>
+          </tr>
         {% endif %}
         <tr>
           <th>{% trans "Default mailbox quota" %}</a></th>
diff --git a/modoboa/admin/tests/test_account.py b/modoboa/admin/tests/test_account.py
index b0927329b..a9dcd887b 100644
--- a/modoboa/admin/tests/test_account.py
+++ b/modoboa/admin/tests/test_account.py
@@ -205,11 +205,11 @@ class AccountTestCase(ModoTestCase):
         dom.quota = 100
         dom.save(update_fields=["quota"])
         # 2 x 10MB
-        self.assertEqual(dom.quota_usage, 20)
+        self.assertEqual(dom.allocated_quota, 20)
         self._set_quota("user@test.com", 80)
-        del dom.quota_usage
+        del dom.allocated_quota
         # 10 + 80 < 100 => ok
-        self.assertEqual(dom.quota_usage, 90)
+        self.assertEqual(dom.allocated_quota, 90)
         # 30 + 80 > 100 => failure
         self._set_quota("admin@test.com", 30, 400)
 
diff --git a/modoboa/admin/views/domain.py b/modoboa/admin/views/domain.py
index 39eba12f2..1f9069bcd 100644
--- a/modoboa/admin/views/domain.py
+++ b/modoboa/admin/views/domain.py
@@ -28,7 +28,7 @@ from modoboa.lib.listing import get_sort_order, get_listing_page
 
 from ..forms import DomainForm, DomainWizard
 from ..lib import get_domains
-from ..models import Domain, Mailbox
+from ..models import Domain, Mailbox, Quota
 from .. import signals
 
 
@@ -176,10 +176,19 @@ class DomainDetailView(
         result = signals.extra_domain_dashboard_widgets.send(
             self.__class__, user=self.request.user, domain=self.object)
         parameters = self.request.localconfig.parameters
+        used_quota = int(
+            Quota.objects.get_domain_usage(self.object) / 1048576)
+        used_quota_in_percent = int(
+            used_quota / float(self.object.quota) * 100)
+        allocated_quota = (
+            self.object.allocated_quota_in_percent - used_quota_in_percent)
         context.update({
             "templates": {"left": [], "right": []},
             "enable_mx_checks": parameters.get_value("enable_mx_checks"),
             "enable_dnsbl_checks": parameters.get_value("enable_dnsbl_checks"),
+            "used_quota": used_quota,
+            "used_quota_in_percent": used_quota_in_percent,
+            "allocated_quota": allocated_quota
         })
         for receiver, widgets in result:
             for widget in widgets: