diff --git a/lib/data/models/task_model.dart b/lib/data/models/task_model.dart
index d8ce185db..d008a7a14 100644
--- a/lib/data/models/task_model.dart
+++ b/lib/data/models/task_model.dart
@@ -6,6 +6,7 @@ import 'package:invoiceninja_flutter/data/models/company_model.dart';
 import 'package:invoiceninja_flutter/data/models/entities.dart';
 import 'package:invoiceninja_flutter/data/models/models.dart';
 import 'package:invoiceninja_flutter/utils/formatting.dart';
+import 'dart:convert';
 
 part 'task_model.g.dart';
 
@@ -87,6 +88,30 @@ abstract class TaskEntity extends Object
 
   int get duration;
 
+  List<List <int>> get timeDetails {
+    final List<List <int>> details = [];
+
+    final List<dynamic> log = jsonDecode(timeLog);
+    log.forEach((dynamic detail) {
+      details.add([
+        (detail as List)[0],
+        (detail as List)[1],
+      ]);
+    });
+
+    return details;
+  }
+
+  int get calculateDuration {
+    int duration = 0;
+
+    timeDetails.forEach((detail) {
+      duration += detail[1] - detail[0];
+    });
+
+    return duration;
+  }
+
   @nullable
   @BuiltValueField(wireName: 'invoice_id')
   int get invoiceId;
diff --git a/lib/ui/task/view/task_view.dart b/lib/ui/task/view/task_view.dart
index 0d1b60909..903ed3b0e 100644
--- a/lib/ui/task/view/task_view.dart
+++ b/lib/ui/task/view/task_view.dart
@@ -9,6 +9,7 @@ import 'package:invoiceninja_flutter/ui/app/icon_message.dart';
 import 'package:invoiceninja_flutter/ui/app/one_value_header.dart';
 import 'package:invoiceninja_flutter/ui/task/view/task_view_vm.dart';
 import 'package:invoiceninja_flutter/ui/app/form_card.dart';
+import 'package:invoiceninja_flutter/utils/formatting.dart';
 import 'package:invoiceninja_flutter/utils/icons.dart';
 import 'package:invoiceninja_flutter/utils/localization.dart';
 
@@ -49,7 +50,7 @@ class _TaskViewState extends State<TaskView> {
       final widgets = <Widget>[
         OneValueHeader(
           label: localization.duration,
-          value: '',
+          value: task.calculateDuration.toString(),
         ),
       ];