diff --git a/app/(tabs)/assignments.tsx b/app/(tabs)/assignments.tsx
index 69190ab..8fb9f77 100644
--- a/app/(tabs)/assignments.tsx
+++ b/app/(tabs)/assignments.tsx
@@ -1,4 +1,5 @@
 import { defaultStyles } from '@/constants/defaultStyles';
+import { CheckSubjectCompletion } from '@/lib/progress';
 import { supabase } from '@/lib/supabase';
 import type { Assignment, Task } from '@/lib/types';
 import { Ionicons } from '@expo/vector-icons';
@@ -97,7 +98,7 @@ export default function Assignments() {
     }, [session])
   );
 
-  const DeleteAssignment = async (aId: string) => {
+  const DeleteAssignment = async (aId: string, sId: string) => {
     Alert.alert(
       'Delete Assignment',
       'Are you sure you want to delete this assignment?',
@@ -121,6 +122,13 @@ export default function Assignments() {
             }
 
             Alert.alert('Assignment deleted successfully!');
+
+            try {
+              await CheckSubjectCompletion(sId);
+            } catch {
+              Alert.alert("Failed to update subject status");
+            }
+
             GetAssignments();
           },
         },
@@ -296,7 +304,7 @@ export default function Assignments() {
 
                     <Pressable
                       className="flex-1 items-center justify-center rounded-2xl border border-app-border bg-app-surface py-3"
-                      onPress={() => DeleteAssignment(item.aId)}
+                      onPress={() => DeleteAssignment(item.aId, item.sId)}
                     >
                       <Text className="text-sm font-bold text-status-danger">
                         Delete
diff --git a/app/(tabs)/subjects.tsx b/app/(tabs)/subjects.tsx
index 323d021..f5f5f79 100644
--- a/app/(tabs)/subjects.tsx
+++ b/app/(tabs)/subjects.tsx
@@ -1,6 +1,6 @@
 import { defaultStyles } from '@/constants/defaultStyles';
 import { supabase } from '@/lib/supabase';
-import type { Subject } from '@/lib/types';
+import type { Assignment, Subject } from '@/lib/types';
 import { Ionicons } from '@expo/vector-icons';
 import { Session } from '@supabase/supabase-js';
 import { router, Stack, useFocusEffect } from 'expo-router';
@@ -15,6 +15,7 @@ import {
 
 export default function Subjects() {
   const [subjects, SetSubjects] = useState<Subject[]>([]);
+  const [assignmentsBySubject, SetAssignmentsBySubject] = useState<Record<string, Assignment[]>>({});
   const [session, SetSession] = useState<Session | null>(null);
 
   const subjectSections = [
@@ -45,17 +46,47 @@ export default function Subjects() {
   }, []);
 
   const GetSubjects = async () => {
-    const { data, error } = await supabase
+    const { data: subjectsData, error: subjectsError } = await supabase
       .from('subjects')
       .select('*')
       .order('lastChanged', { ascending: false });
 
-    if (error) {
+    if (subjectsError) {
       Alert.alert('Subjects could not be fetched, please try again');
       return;
     }
 
-    SetSubjects(data ?? []);
+    const subjectRows = subjectsData ?? [];
+    SetSubjects(subjectsData ?? []);
+
+    if (subjectRows.length === 0) {
+      SetAssignmentsBySubject({});
+      return;
+    }
+    
+    const sIds = subjectRows.map((subject) => subject.sId);
+    
+    const { data: assignmentsData, error: assignmentsError } = await supabase
+      .from('assignments')
+      .select('*')
+      .in('sId', sIds);
+    
+    if (assignmentsError) {
+      Alert.alert('Subject assignments could not be fetched, please try again');
+      SetAssignmentsBySubject({});
+      return;
+    }
+    
+    const groupedAssignments: Record<string, Assignment[]> = {};
+    
+    for (const assignment of assignmentsData ?? []) {
+      if (!groupedAssignments[assignment.sId]) {
+        groupedAssignments[assignment.sId] = [];
+      }
+      groupedAssignments[assignment.sId].push(assignment);
+    }
+    
+    SetAssignmentsBySubject(groupedAssignments);
   };
 
   useFocusEffect(
@@ -169,6 +200,9 @@ export default function Subjects() {
           renderItem={({ item }) => {
             const isOwner = session?.user.id === item.uId;
 
+            const subjectAssignments = assignmentsBySubject[item.sId] ?? [];
+            const progress = subjectAssignments.length === 0 ? 0 : Math.round((subjectAssignments.filter(assignment => assignment.isCompleted).length / subjectAssignments.length) * 100);
+
             return (
               <View className="mb-4 rounded-3xl border border-app-border bg-app-surface p-4 shadow-sm">
                 <Pressable
@@ -219,6 +253,27 @@ export default function Subjects() {
                           {item.isActive ? 'Active' : 'Inactive'}
                         </Text>
                       </View>
+                      <View style={{ marginTop: 10 }}>
+                        <Text style={{ marginBottom: 4 }}>{progress}%</Text>
+                        
+                        <View
+                          style={{
+                            width: "100%",
+                            height: 12,
+                            backgroundColor: "#D9D9D9",
+                            borderRadius: 999,
+                            overflow: "hidden",
+                          }}
+                        >
+                          <View
+                            style={{
+                              width: `${progress}%`,
+                              height: "100%",
+                              backgroundColor: "#4CAF50",
+                            }}
+                          />
+                        </View>
+                      </View>
                     </View>
                   </View>
                 </Pressable>
diff --git a/app/(tabs)/tasks.tsx b/app/(tabs)/tasks.tsx
index 6b204e4..7e08755 100644
--- a/app/(tabs)/tasks.tsx
+++ b/app/(tabs)/tasks.tsx
@@ -1,4 +1,5 @@
 import { defaultStyles } from '@/constants/defaultStyles';
+import { CheckAssignmentCompletion } from '@/lib/progress';
 import { supabase } from '@/lib/supabase';
 import type { Task } from '@/lib/types';
 import { Ionicons } from '@expo/vector-icons';
@@ -63,7 +64,7 @@ export default function Tasks() {
     }, [session])
   );
 
-  const DeleteTask = async (tId: string) => {
+  const DeleteTask = async (tId: string, aId: string) => {
     Alert.alert(
       'Delete Task',
       'Are you sure you want to delete this task?',
@@ -87,6 +88,13 @@ export default function Tasks() {
             }
 
             Alert.alert('Task deleted successfully!');
+
+            try {
+              await CheckAssignmentCompletion(aId);
+            } catch {
+              Alert.alert("Failed to update assignment completion state");
+            }
+
             GetTasks();
           },
         },
@@ -237,7 +245,7 @@ export default function Tasks() {
 
                     <Pressable
                       className="flex-1 items-center justify-center rounded-2xl border border-app-border bg-app-surface py-3"
-                      onPress={() => DeleteTask(item.tId)}
+                      onPress={() => DeleteTask(item.tId, item.aId)}
                     >
                       <Text className="text-sm font-bold text-status-danger">
                         Delete
diff --git a/app/assignment/createAssignment.tsx b/app/assignment/createAssignment.tsx
index 68be4c6..f377cb0 100644
--- a/app/assignment/createAssignment.tsx
+++ b/app/assignment/createAssignment.tsx
@@ -1,5 +1,6 @@
 import { defaultStyles } from '@/constants/defaultStyles';
 import * as AsyncStorage from '@/lib/asyncStorage';
+import { CheckSubjectCompletion } from '@/lib/progress';
 import { supabase } from '@/lib/supabase';
 import * as Notifications from 'expo-notifications';
 import { router, Stack, useLocalSearchParams } from 'expo-router';
@@ -93,6 +94,14 @@ export default function CreateAssignment() {
       }
     }
 
+    if (sId) {
+      try {
+        await CheckSubjectCompletion(sId);
+      } catch {
+        Alert.alert("Failed to update subject status");
+      }
+    }
+
     SetTitle('');
     SetDescription('');
     SetDeadline('');
diff --git a/app/assignment/editAssignment.tsx b/app/assignment/editAssignment.tsx
index 76e0348..7115942 100644
--- a/app/assignment/editAssignment.tsx
+++ b/app/assignment/editAssignment.tsx
@@ -1,5 +1,6 @@
 import { defaultStyles } from '@/constants/defaultStyles';
 import { GetAssignmentNotificationId, RemoveAssignmentNotificationId, SaveAssignmentNotificationId } from '@/lib/asyncStorage';
+import { CheckSubjectCompletion } from '@/lib/progress';
 import { supabase } from '@/lib/supabase';
 import type { Assignment } from '@/lib/types';
 import * as Notifications from 'expo-notifications';
@@ -115,6 +116,14 @@ export default function EditAssignment() {
       }
     }
 
+    if (assignmentData.sId) {
+      try {
+        await CheckSubjectCompletion(assignmentData.sId);
+      } catch {
+        Alert.alert("Failed to update subject status");
+      }
+    }
+
     router.back();
   }
 
diff --git a/app/assignment/viewDetailsAssignment.tsx b/app/assignment/viewDetailsAssignment.tsx
index 99a97d4..e7dc364 100644
--- a/app/assignment/viewDetailsAssignment.tsx
+++ b/app/assignment/viewDetailsAssignment.tsx
@@ -1,4 +1,5 @@
 import { defaultStyles } from '@/constants/defaultStyles';
+import { CheckAssignmentCompletion, CheckSubjectCompletion } from '@/lib/progress';
 import { supabase } from '@/lib/supabase';
 import type { Assignment, Task } from '@/lib/types';
 import { Session } from '@supabase/supabase-js';
@@ -78,6 +79,17 @@ export default function ViewDetailsAssignment() {
             }
 
             Alert.alert("Assignment deleted successfully!");
+
+            const sId = assignment?.sId;
+
+            if (sId) {
+              try {
+                await CheckSubjectCompletion(sId);
+              } catch {
+                Alert.alert("Failed to update subject status");
+              }
+            }
+
             router.back();
           }
         }
@@ -106,6 +118,15 @@ export default function ViewDetailsAssignment() {
             }
 
             Alert.alert("Task deleted successfully!");
+            
+            if (aId) {
+              try {
+                await CheckAssignmentCompletion(aId);
+              } catch {
+                Alert.alert("Failed to update assignment completion state");
+              }
+            }
+
             GetTasks(aId);
           }
         }
@@ -153,9 +174,10 @@ export default function ViewDetailsAssignment() {
             <View style={defaultStyles.checkbox}>
                 {assignment.isCompleted && <Text style={defaultStyles.checkboxMark}>✓</Text>}
             </View>
-            <View style={{ width: "100%", marginTop: 8 }}>
+            <Text style={defaultStyles.body}>{assignment.lastChanged}</Text>
+            <View style={{ marginTop: 10 }}>
               <Text style={{ marginBottom: 4 }}>{progress}%</Text>
-
+              
               <View
                 style={{
                   width: "100%",
@@ -174,7 +196,6 @@ export default function ViewDetailsAssignment() {
                 />
               </View>
             </View>
-            <Text style={defaultStyles.body}>{assignment.lastChanged}</Text>
 
             <Button title="Edit" onPress={() => router.push({pathname: "/assignment/editAssignment", params: { aId: assignment.aId }})} />
             <Button title="Delete" onPress={() => DeleteAssignment(assignment.aId)} />
diff --git a/app/subject/viewDetailsSubject.tsx b/app/subject/viewDetailsSubject.tsx
index 78478eb..a8a634f 100644
--- a/app/subject/viewDetailsSubject.tsx
+++ b/app/subject/viewDetailsSubject.tsx
@@ -1,4 +1,5 @@
 import { defaultStyles } from '@/constants/defaultStyles';
+import { CheckSubjectCompletion } from '@/lib/progress';
 import { supabase } from '@/lib/supabase';
 import type { Assignment, Subject } from '@/lib/types';
 import { Session } from '@supabase/supabase-js';
@@ -106,6 +107,15 @@ export default function ViewDetailsSubject() {
             }
 
             Alert.alert("Assignment deleted successfully!");
+            
+            if (sId) {
+              try {
+                await CheckSubjectCompletion(sId);
+              } catch {
+                Alert.alert("Failed to update subject status");
+              }
+            }
+
             GetAssignments(sId);
           }
         }
@@ -113,9 +123,7 @@ export default function ViewDetailsSubject() {
     )
   }
 
-  const CalculateSubjectCompletion = async () => {
-    
-  }
+  const progress = assignments.length === 0 ? 0 : Math.round((assignments.filter(assignment => assignment.isCompleted).length / assignments.length) * 100);
 
   return (
     <View style={defaultStyles.container}>
@@ -155,6 +163,27 @@ export default function ViewDetailsSubject() {
                 {subject.isActive && <Text style={defaultStyles.checkboxMark}>✓</Text>}
             </View>
             <Text style={defaultStyles.body}>{subject.lastChanged}</Text>
+            <View style={{ marginTop: 10 }}>
+              <Text style={{ marginBottom: 4 }}>{progress}%</Text>
+              
+              <View
+                style={{
+                  width: "100%",
+                  height: 12,
+                  backgroundColor: "#D9D9D9",
+                  borderRadius: 999,
+                  overflow: "hidden",
+                }}
+              >
+                <View
+                  style={{
+                    width: `${progress}%`,
+                    height: "100%",
+                    backgroundColor: "#4CAF50",
+                  }}
+                />
+              </View>
+            </View>
 
             <Button title="Edit" onPress={() => router.push({pathname: "/subject/editSubject", params: { sId: subject.sId }})} />
             <Button title="Delete" onPress={() => DeleteSubject(subject.sId)} />
diff --git a/lib/progress.ts b/lib/progress.ts
index 073da7b..7ab2507 100644
--- a/lib/progress.ts
+++ b/lib/progress.ts
@@ -11,5 +11,19 @@ export async function CheckAssignmentCompletion(aId: string) {
 
   const { error: updateError } = await supabase.from("assignments").update({ isCompleted: allCompleted, lastChanged: new Date().toISOString()}).eq("aId", aId);
 
+  if (updateError) throw updateError;
+}
+
+export async function CheckSubjectCompletion(sId: string) {
+  const { data, error } = await supabase.from("assignments").select("aId, isCompleted").eq("sId", sId);
+
+  if (error) throw error;
+
+  const assignments = data ?? [];
+
+  const allCompleted = assignments.length > 0 && assignments.every((assignment) => assignment.isCompleted === true);
+
+  const { error: updateError } = await supabase.from("subjects").update({ isActive: allCompleted, lastChanged: new Date().toISOString()}).eq("sId", sId);
+
   if (updateError) throw updateError;
 }
\ No newline at end of file
diff --git a/notes/work-report-2026-04-22-progess-bars.md b/notes/work-report-2026-04-22-progess-bars.md
new file mode 100644
index 0000000..25cdf80
--- /dev/null
+++ b/notes/work-report-2026-04-22-progess-bars.md
@@ -0,0 +1,38 @@
+# Progress Tracking (Assignments & Subjects)
+
+## What was done
+- Implemented progress tracking for both assignments and subjects
+- Used `Task.isCompleted` as the source of truth
+- Synced `Assignment.isCompleted` based on task completion
+
+## Logic implemented
+- Created `CheckAssignmentCompletion(aId)`
+- Assignment is marked completed only if all its tasks are completed
+- Assignment remains incomplete if:
+  - Any task is incomplete
+  - No tasks exist
+
+## Data handling
+- Fetched assignments from Supabase
+- Fetched all related tasks using assignment IDs
+- Grouped tasks by `aId` into `tasksByAssignment`
+- Used grouped data to calculate progress efficiently
+
+## Progress calculation
+- Assignment progress:
+  - completed tasks / total tasks
+- Subject progress:
+  - completed tasks across all assignments / total tasks
+
+## UI work
+- Added progress bars to:
+  - Assignment cards
+  - Subject views
+- Used basic inline styling for progress bars
+- Fixed layout issues caused by incorrect placement inside `flex-row`
+- Moved progress bar into content column to prevent UI breaking
+
+## Result
+- Progress updates dynamically based on task completion
+- Assignment completion stays in sync with tasks
+- UI correctly displays both assignment and subject progress
\ No newline at end of file