diff --git a/homeassistant/components/mazda/sensor.py b/homeassistant/components/mazda/sensor.py
index c688ac62637..715b274b6f5 100644
--- a/homeassistant/components/mazda/sensor.py
+++ b/homeassistant/components/mazda/sensor.py
@@ -116,7 +116,8 @@ def _fuel_distance_remaining_value(data, unit_system):
 
 def _odometer_value(data, unit_system):
     """Get the odometer value."""
-    return round(unit_system.length(data["status"]["odometerKm"], LENGTH_KILOMETERS))
+    # In order to match the behavior of the Mazda mobile app, we always round down
+    return int(unit_system.length(data["status"]["odometerKm"], LENGTH_KILOMETERS))
 
 
 def _front_left_tire_pressure_value(data, unit_system):
diff --git a/tests/components/mazda/test_sensor.py b/tests/components/mazda/test_sensor.py
index 763e1490e89..2284101fa84 100644
--- a/tests/components/mazda/test_sensor.py
+++ b/tests/components/mazda/test_sensor.py
@@ -63,7 +63,7 @@ async def test_sensors(hass):
     assert state.attributes.get(ATTR_ICON) == "mdi:speedometer"
     assert state.attributes.get(ATTR_UNIT_OF_MEASUREMENT) == LENGTH_KILOMETERS
     assert state.attributes.get(ATTR_STATE_CLASS) == SensorStateClass.TOTAL_INCREASING
-    assert state.state == "2796"
+    assert state.state == "2795"
     entry = entity_registry.async_get("sensor.my_mazda3_odometer")
     assert entry
     assert entry.unique_id == "JM000000000000000_odometer"