diff --git a/backend/LexBoxApi/GraphQL/ProjectMutations.cs b/backend/LexBoxApi/GraphQL/ProjectMutations.cs
index ccdb9046e9..2f6df40394 100644
--- a/backend/LexBoxApi/GraphQL/ProjectMutations.cs
+++ b/backend/LexBoxApi/GraphQL/ProjectMutations.cs
@@ -355,6 +355,24 @@ public async Task<IQueryable<Project>> SetRetentionPolicy(
         return dbContext.Projects.Where(p => p.Id == input.ProjectId);
     }
 
+    [Error<NotFoundException>]
+    [Error<DbError>]
+    [Error<UnauthorizedAccessException>]
+    [UseMutationConvention]
+    [UseFirstOrDefault]
+    [UseProjection]
+    public async Task<IQueryable<Project>> UpdateProjectRepoSizeInKb(string code,
+        IPermissionService permissionService,
+        ProjectService projectService,
+        LexBoxDbContext dbContext)
+    {
+        var projectId = await projectService.LookupProjectId(code);
+        await permissionService.AssertCanViewProject(projectId);
+        if (projectId == default) throw NotFoundException.ForType<Project>();
+        await projectService.UpdateRepoSizeInKb(code);
+        return dbContext.Projects.Where(p => p.Id == projectId);
+    }
+
     [Error<NotFoundException>]
     [Error<DbError>]
     [Error<UnauthorizedAccessException>]
diff --git a/backend/LexBoxApi/Services/ProjectService.cs b/backend/LexBoxApi/Services/ProjectService.cs
index 9732b1f29f..298f9faffc 100644
--- a/backend/LexBoxApi/Services/ProjectService.cs
+++ b/backend/LexBoxApi/Services/ProjectService.cs
@@ -244,6 +244,16 @@ public async Task UpdateProjectMetadata(Project project)
         // Caller is responsible for caling dbContext.SaveChangesAsync()
     }
 
+    public async Task<int?> UpdateRepoSizeInKb(string projectCode)
+    {
+        var project = await dbContext.Projects.FirstOrDefaultAsync(p => p.Code == projectCode);
+        if (project is null) return null;
+        var size = await hgService.GetRepoSizeInKb(projectCode);
+        project.RepoSizeInKb = size;
+        await dbContext.SaveChangesAsync();
+        return size;
+    }
+
     public async Task ResetLexEntryCount(string projectCode)
     {
         var project = await dbContext.Projects
diff --git a/frontend/schema.graphql b/frontend/schema.graphql
index 06060b836c..ec15ec026a 100644
--- a/frontend/schema.graphql
+++ b/frontend/schema.graphql
@@ -256,6 +256,7 @@ type Mutation {
   changeProjectDescription(input: ChangeProjectDescriptionInput!): ChangeProjectDescriptionPayload! @cost(weight: "10")
   setProjectConfidentiality(input: SetProjectConfidentialityInput!): SetProjectConfidentialityPayload! @cost(weight: "10")
   setRetentionPolicy(input: SetRetentionPolicyInput!): SetRetentionPolicyPayload! @cost(weight: "10")
+  updateProjectRepoSizeInKb(input: UpdateProjectRepoSizeInKbInput!): UpdateProjectRepoSizeInKbPayload! @cost(weight: "10")
   updateProjectLexEntryCount(input: UpdateProjectLexEntryCountInput!): UpdateProjectLexEntryCountPayload! @cost(weight: "10")
   updateProjectLanguageList(input: UpdateProjectLanguageListInput!): UpdateProjectLanguageListPayload! @cost(weight: "10")
   updateLangProjectId(input: UpdateLangProjectIdInput!): UpdateLangProjectIdPayload! @cost(weight: "10")
@@ -384,6 +385,7 @@ type Project {
   flexProjectMetadata: FlexProjectMetadata
   organizations: [Organization!]!
   lastCommit: DateTime
+  repoSizeInKb: Int
   deletedDate: DateTime
   resetStatus: ResetStatus!
   projectOrigin: ProjectMigrationStatus!
@@ -512,6 +514,11 @@ type UpdateProjectLexEntryCountPayload {
   errors: [UpdateProjectLexEntryCountError!]
 }
 
+type UpdateProjectRepoSizeInKbPayload {
+  project: Project
+  errors: [UpdateProjectRepoSizeInKbError!]
+}
+
 type User {
   email: String @authorize(policy: "AdminRequiredPolicy")
   emailVerified: Boolean! @authorize(policy: "AdminRequiredPolicy")
@@ -619,6 +626,8 @@ union UpdateProjectLanguageListError = NotFoundError | DbError | UnauthorizedAcc
 
 union UpdateProjectLexEntryCountError = NotFoundError | DbError | UnauthorizedAccessError
 
+union UpdateProjectRepoSizeInKbError = NotFoundError | DbError | UnauthorizedAccessError
+
 input AddProjectMemberInput {
   projectId: UUID!
   usernameOrEmail: String
@@ -930,6 +939,7 @@ input ProjectFilterInput {
   users: ListFilterInputTypeOfProjectUsersFilterInput
   organizations: ListFilterInputTypeOfOrganizationFilterInput
   lastCommit: DateTimeOperationFilterInput
+  repoSizeInKb: IntOperationFilterInput
   deletedDate: DateTimeOperationFilterInput
   resetStatus: ResetStatusOperationFilterInput
   projectOrigin: ProjectMigrationStatusOperationFilterInput
@@ -964,6 +974,7 @@ input ProjectSortInput {
   isConfidential: SortEnumType @cost(weight: "10")
   flexProjectMetadata: FlexProjectMetadataSortInput @cost(weight: "10")
   lastCommit: SortEnumType @cost(weight: "10")
+  repoSizeInKb: SortEnumType @cost(weight: "10")
   deletedDate: SortEnumType @cost(weight: "10")
   resetStatus: SortEnumType @cost(weight: "10")
   projectOrigin: SortEnumType @cost(weight: "10")
@@ -1093,6 +1104,10 @@ input UpdateProjectLexEntryCountInput {
   code: String!
 }
 
+input UpdateProjectRepoSizeInKbInput {
+  code: String!
+}
+
 input UserFilterInput {
   and: [UserFilterInput!]
   or: [UserFilterInput!]