diff --git a/src/tribler-core/tribler_core/upgrade/db8_to_db10.py b/src/tribler-core/tribler_core/upgrade/db8_to_db10.py
index 14fd2d5380c..c2303644294 100644
--- a/src/tribler-core/tribler_core/upgrade/db8_to_db10.py
+++ b/src/tribler-core/tribler_core/upgrade/db8_to_db10.py
@@ -229,7 +229,7 @@ def fts_callback_handler():
 
 
 def calc_progress(duration_now, duration_half=60.0):
-    result = 100 * ( 1 - 1 / (1 + duration_now / duration_half) ** 2)
+    result = 100 * ( 1 - 1 / (1 + duration_now / (duration_half + 1)) ** 2)
     return result
 
 
diff --git a/src/tribler-core/tribler_core/upgrade/tests/test_upgrader.py b/src/tribler-core/tribler_core/upgrade/tests/test_upgrader.py
index c9b1e743a48..65ee01047c2 100644
--- a/src/tribler-core/tribler_core/upgrade/tests/test_upgrader.py
+++ b/src/tribler-core/tribler_core/upgrade/tests/test_upgrader.py
@@ -12,6 +12,7 @@
 from tribler_core.modules.metadata_store.orm_bindings.channel_metadata import CHANNEL_DIR_NAME_LENGTH
 from tribler_core.modules.metadata_store.store import CURRENT_DB_VERSION, MetadataStore
 from tribler_core.tests.tools.common import TESTS_DATA_DIR
+from tribler_core.upgrade.db8_to_db10 import calc_progress
 from tribler_core.upgrade.upgrade import cleanup_noncompliant_channel_torrents
 from tribler_core.utilities.configparser import CallbackConfigParser
 
@@ -154,3 +155,19 @@ async def test_upgrade_pony_8to10(upgrader, session):
         assert int(mds.MiscData.get(name="db_version").value) == CURRENT_DB_VERSION
         assert mds.ChannelNode.select().count() == 23
     mds.shutdown()
+
+def test_calc_progress():
+    EPSILON = 0.001
+    assert calc_progress(0) == pytest.approx(0.0, abs=EPSILON)
+    assert calc_progress(0, 1) == pytest.approx(0.0, abs=EPSILON)
+
+    assert calc_progress(1, 0) == pytest.approx(75.0, abs=EPSILON)
+    assert calc_progress(10, 0) == pytest.approx(99.173553, abs=EPSILON)
+
+    assert calc_progress(0, 100) == pytest.approx(0.0, abs=EPSILON)
+    assert calc_progress(10, 100) == pytest.approx(17.206395, abs=EPSILON)
+    assert calc_progress(50, 100) == pytest.approx(55.260734, abs=EPSILON)
+    assert calc_progress(80, 100) == pytest.approx(68.862366, abs=EPSILON)
+    assert calc_progress(100, 100) == pytest.approx(74.750624, abs=EPSILON)
+    assert calc_progress(200, 100) == pytest.approx(88.740742, abs=EPSILON)
+    assert calc_progress(1000, 100) == pytest.approx(99.158472, abs=EPSILON)