diff --git a/index.tmpl b/index.tmpl
index f2c3eeb..3797976 100644
--- a/index.tmpl
+++ b/index.tmpl
@@ -57,6 +57,7 @@
                     <th style="width: 10%">ID</th>
                     <th style="width: 50%">Description</th>
                     <th style="width: 20%">Created at</th>
+                    <th style="width: 25%">Exists for</th>
                     <th style="width: 15%">Actions</th>
                 </tr>
             </thead>
@@ -67,6 +68,7 @@
                         <td>{{ $session.Id }}</td>
                         <td>{{ $session.Description }}</td>
                         <td>{{ $session.CreatedAt.Format "02.01.2006 15:04:05" }}</td>
+                        <td>{{ $session.ExistsFor.Round 1000000000 }}</td> {{/* 1 second */}}
                         <td>
                             <form method="post" action="/end_session" enctype="multipart/form-data">
                                 <input type="hidden" name="session_id" value="{{ $session.Id }}">
diff --git a/sessions/sessions.go b/sessions/sessions.go
index 401e9f5..12d23d0 100644
--- a/sessions/sessions.go
+++ b/sessions/sessions.go
@@ -8,6 +8,10 @@ type Session struct {
 	CreatedAt   time.Time
 }
 
+func (s *Session) ExistsFor() time.Duration {
+	return time.Now().Sub(s.CreatedAt)
+}
+
 type Storage interface {
 	// Check if the storage contains any sessions
 	HasSessions() (bool, error)