diff --git a/backend/btrixcloud/colls.py b/backend/btrixcloud/colls.py
index 3815c9f6..58719de8 100644
--- a/backend/btrixcloud/colls.py
+++ b/backend/btrixcloud/colls.py
@@ -182,7 +182,7 @@ class CollectionOps:
         aggregate = [{"$match": match_query}]
 
         if sort_by:
-            if sort_by not in ("modified", "name", "description"):
+            if sort_by not in ("modified", "name", "description", "totalSize"):
                 raise HTTPException(status_code=400, detail="invalid_sort_by")
             if sort_direction not in (1, -1):
                 raise HTTPException(status_code=400, detail="invalid_sort_direction")
@@ -267,6 +267,7 @@ async def update_collection_counts_and_tags(
     """Set current crawl info in config when crawl begins"""
     crawl_count = 0
     page_count = 0
+    total_size = 0
     tags = []
 
     cursor = crawls.find({"collections": collection_id})
@@ -275,6 +276,9 @@ async def update_collection_counts_and_tags(
         if crawl["state"] not in SUCCESSFUL_STATES:
             continue
         crawl_count += 1
+        files = crawl.get("files", [])
+        for file in files:
+            total_size += file.get("size", 0)
         if crawl.get("stats"):
             page_count += crawl.get("stats", {}).get("done", 0)
         if crawl.get("tags"):
@@ -288,6 +292,7 @@ async def update_collection_counts_and_tags(
             "$set": {
                 "crawlCount": crawl_count,
                 "pageCount": page_count,
+                "totalSize": total_size,
                 "tags": sorted_tags,
             }
         },
diff --git a/backend/btrixcloud/db.py b/backend/btrixcloud/db.py
index 7f94f525..d17e5c39 100644
--- a/backend/btrixcloud/db.py
+++ b/backend/btrixcloud/db.py
@@ -15,7 +15,7 @@ from pymongo.errors import InvalidName
 from .migrations import BaseMigration
 
 
-CURR_DB_VERSION = "0009"
+CURR_DB_VERSION = "0010"
 
 
 # ============================================================================
diff --git a/backend/btrixcloud/migrations/migration_0010_collection_total_size.py b/backend/btrixcloud/migrations/migration_0010_collection_total_size.py
new file mode 100644
index 00000000..4fa2a291
--- /dev/null
+++ b/backend/btrixcloud/migrations/migration_0010_collection_total_size.py
@@ -0,0 +1,36 @@
+"""
+Migration 0010 - Precomputing collection total size
+"""
+from btrixcloud.colls import update_collection_counts_and_tags
+from btrixcloud.migrations import BaseMigration
+
+
+MIGRATION_VERSION = "0010"
+
+
+class Migration(BaseMigration):
+    """Migration class."""
+
+    def __init__(self, mdb, migration_version=MIGRATION_VERSION):
+        super().__init__(mdb, migration_version)
+
+    async def migrate_up(self):
+        """Perform migration up.
+
+        Recompute collection data to include totalSize.
+        """
+        # pylint: disable=duplicate-code
+        colls = self.mdb["collections"]
+        crawls = self.mdb["crawls"]
+
+        colls_to_update = [res async for res in colls.find({})]
+        if not colls_to_update:
+            return
+
+        for coll in colls_to_update:
+            coll_id = coll["_id"]
+            try:
+                await update_collection_counts_and_tags(colls, crawls, coll_id)
+            # pylint: disable=broad-exception-caught
+            except Exception as err:
+                print(f"Unable to update collection {coll_id}: {err}", flush=True)
diff --git a/backend/btrixcloud/models.py b/backend/btrixcloud/models.py
index 35263499..a5929ef6 100644
--- a/backend/btrixcloud/models.py
+++ b/backend/btrixcloud/models.py
@@ -463,6 +463,7 @@ class Collection(BaseMongoModel):
 
     crawlCount: Optional[int] = 0
     pageCount: Optional[int] = 0
+    totalSize: Optional[int] = 0
 
     # Sorted by count, descending
     tags: Optional[List[str]] = []
diff --git a/backend/test/test_collections.py b/backend/test/test_collections.py
index 0e3707ae..3e289754 100644
--- a/backend/test/test_collections.py
+++ b/backend/test/test_collections.py
@@ -98,6 +98,7 @@ def test_update_collection(
     assert data["description"] == DESCRIPTION
     assert data["crawlCount"] == 1
     assert data["pageCount"] > 0
+    assert data["totalSize"] > 0
     global modified
     modified = data["modified"]
     assert modified
@@ -172,6 +173,7 @@ def test_add_remove_crawl_from_collection(
     assert data["id"] == _coll_id
     assert data["crawlCount"] == 2
     assert data["pageCount"] > 0
+    assert data["totalSize"] > 0
     assert data["modified"] >= modified
     assert data["tags"] == ["wr-test-2", "wr-test-1"]
 
@@ -193,6 +195,7 @@ def test_add_remove_crawl_from_collection(
     assert data["id"] == _coll_id
     assert data["crawlCount"] == 0
     assert data["pageCount"] == 0
+    assert data["totalSize"] == 0
     assert data["modified"] >= modified
     assert data.get("tags", []) == []
 
@@ -220,6 +223,7 @@ def test_add_remove_crawl_from_collection(
     assert data["id"] == _coll_id
     assert data["crawlCount"] == 2
     assert data["pageCount"] > 0
+    assert data["totalSize"] > 0
     assert data["modified"] >= modified
     assert data["tags"] == ["wr-test-2", "wr-test-1"]
 
@@ -237,6 +241,7 @@ def test_get_collection(crawler_auth_headers, default_org_id):
     assert data["description"] == DESCRIPTION
     assert data["crawlCount"] == 2
     assert data["pageCount"] > 0
+    assert data["totalSize"] > 0
     assert data["modified"] >= modified
     assert data["tags"] == ["wr-test-2", "wr-test-1"]
 
@@ -256,6 +261,7 @@ def test_get_collection_replay(
     assert data["description"] == DESCRIPTION
     assert data["crawlCount"] == 2
     assert data["pageCount"] > 0
+    assert data["totalSize"] > 0
     assert data["modified"] >= modified
     assert data["tags"] == ["wr-test-2", "wr-test-1"]
 
@@ -292,6 +298,7 @@ def test_add_upload_to_collection(crawler_auth_headers, default_org_id):
     assert data["id"] == _coll_id
     assert data["crawlCount"] == 3
     assert data["pageCount"] > 0
+    assert data["totalSize"] > 0
     assert data["modified"]
     assert data["tags"] == ["wr-test-2", "wr-test-1"]
 
@@ -323,6 +330,7 @@ def test_list_collections(
     assert first_coll["description"] == DESCRIPTION
     assert first_coll["crawlCount"] == 3
     assert first_coll["pageCount"] > 0
+    assert first_coll["totalSize"] > 0
     assert first_coll["modified"]
     assert first_coll["tags"] == ["wr-test-2", "wr-test-1"]
 
@@ -333,6 +341,7 @@ def test_list_collections(
     assert second_coll.get("description") is None
     assert second_coll["crawlCount"] == 1
     assert second_coll["pageCount"] > 0
+    assert second_coll["totalSize"] > 0
     assert second_coll["modified"]
     assert second_coll["tags"] == ["wr-test-2"]
 
@@ -349,6 +358,7 @@ def test_remove_upload_from_collection(crawler_auth_headers, default_org_id):
     assert data["id"] == _coll_id
     assert data["crawlCount"] == 2
     assert data["pageCount"] > 0
+    assert data["totalSize"] > 0
     assert data["modified"] >= modified
     assert data.get("tags") == ["wr-test-2", "wr-test-1"]
 
@@ -499,6 +509,46 @@ def test_filter_sort_collections(
     items = data["items"]
     assert items[0]["modified"] >= items[1]["modified"]
 
+    # Test sorting by size, ascending
+    r = requests.get(
+        f"{API_PREFIX}/orgs/{default_org_id}/collections?sortBy=totalSize",
+        headers=crawler_auth_headers,
+    )
+    assert r.status_code == 200
+    data = r.json()
+    assert data["total"] == 2
+
+    items = data["items"]
+    assert items[0]["totalSize"] <= items[1]["totalSize"]
+
+    # Test sorting by size, descending
+    r = requests.get(
+        f"{API_PREFIX}/orgs/{default_org_id}/collections?sortBy=totalSize&sortDirection=-1",
+        headers=crawler_auth_headers,
+    )
+    assert r.status_code == 200
+    data = r.json()
+    assert data["total"] == 2
+
+    items = data["items"]
+    assert items[0]["totalSize"] >= items[1]["totalSize"]
+
+    # Invalid sort value
+    r = requests.get(
+        f"{API_PREFIX}/orgs/{default_org_id}/collections?sortBy=invalid",
+        headers=crawler_auth_headers,
+    )
+    assert r.status_code == 400
+    assert r.json()["detail"] == "invalid_sort_by"
+
+    # Invalid sort_direction value
+    r = requests.get(
+        f"{API_PREFIX}/orgs/{default_org_id}/collections?sortBy=modified&sortDirection=0",
+        headers=crawler_auth_headers,
+    )
+    assert r.status_code == 400
+    assert r.json()["detail"] == "invalid_sort_direction"
+
 
 def test_delete_collection(crawler_auth_headers, default_org_id, crawler_crawl_id):
     # Delete second collection