diff --git a/freqtrade/optimize/__init__.py b/freqtrade/optimize/__init__.py
index 3376d0075..e837a09bd 100644
--- a/freqtrade/optimize/__init__.py
+++ b/freqtrade/optimize/__init__.py
@@ -91,10 +91,11 @@ def validate_backtest_data(data: Dict[str, DataFrame], min_date: datetime,
     expected_frames = int((max_date - min_date).total_seconds() // 60 // ticker_interval_mins)
     found_missing = False
     for pair, df in data.items():
-        if len(df) < expected_frames:
+        dflen = len(df)
+        if dflen < expected_frames:
             found_missing = True
-            logger.warning('%s has missing frames: expected %s, got %s',
-                           pair, expected_frames, len(df))
+            logger.warning("%s has missing frames: expected %s, got %s, that's %s missing values",
+                           pair, expected_frames, dflen, expected_frames - dflen)
     return found_missing
 
 
diff --git a/freqtrade/tests/optimize/test_optimize.py b/freqtrade/tests/optimize/test_optimize.py
index 32db5abd0..2975a3e4b 100644
--- a/freqtrade/tests/optimize/test_optimize.py
+++ b/freqtrade/tests/optimize/test_optimize.py
@@ -468,8 +468,9 @@ def test_validate_backtest_data_warn(default_conf, mocker, caplog) -> None:
     assert optimize.validate_backtest_data(data, min_date, max_date,
                                            constants.TICKER_INTERVAL_MINUTES["1m"])
     assert len(caplog.record_tuples) == 1
-    assert log_has('UNITTEST/BTC has missing frames: expected 14396, got 13680',
-                   caplog.record_tuples)
+    assert log_has(
+        "UNITTEST/BTC has missing frames: expected 14396, got 13680, that's 716 missing values",
+        caplog.record_tuples)
 
 
 def test_validate_backtest_data(default_conf, mocker, caplog) -> None:
@@ -491,4 +492,3 @@ def test_validate_backtest_data(default_conf, mocker, caplog) -> None:
     assert not optimize.validate_backtest_data(data, min_date, max_date,
                                                constants.TICKER_INTERVAL_MINUTES["5m"])
     assert len(caplog.record_tuples) == 0
-