diff --git a/homeassistant/components/group/sensor.py b/homeassistant/components/group/sensor.py
index 3c8f7059901..47695a275fc 100644
--- a/homeassistant/components/group/sensor.py
+++ b/homeassistant/components/group/sensor.py
@@ -1,4 +1,5 @@
 """Platform allowing several sensors to be grouped into one sensor to provide numeric combinations."""
+
 from __future__ import annotations
 
 from collections.abc import Callable
@@ -13,6 +14,7 @@ from homeassistant.components.input_number import DOMAIN as INPUT_NUMBER_DOMAIN
 from homeassistant.components.number import DOMAIN as NUMBER_DOMAIN
 from homeassistant.components.sensor import (
     CONF_STATE_CLASS,
+    DEVICE_CLASS_UNITS,
     DEVICE_CLASSES_SCHEMA,
     DOMAIN,
     PLATFORM_SCHEMA as PARENT_PLATFORM_SCHEMA,
@@ -313,6 +315,7 @@ class SensorGroup(GroupEntity, SensorEntity):
         self._device_class = device_class
         self._native_unit_of_measurement = unit_of_measurement
         self._valid_units: set[str | None] = set()
+        self._can_convert: bool = False
         self._attr_name = name
         if name == DEFAULT_NAME:
             self._attr_name = f"{DEFAULT_NAME} {sensor_type}".capitalize()
@@ -352,10 +355,18 @@ class SensorGroup(GroupEntity, SensorEntity):
                         self._valid_units
                         and (uom := state.attributes["unit_of_measurement"])
                         in self._valid_units
+                        and self._can_convert is True
                     ):
                         numeric_state = UNIT_CONVERTERS[self.device_class].convert(
                             numeric_state, uom, self.native_unit_of_measurement
                         )
+                    if (
+                        self._valid_units
+                        and (uom := state.attributes["unit_of_measurement"])
+                        not in self._valid_units
+                    ):
+                        raise HomeAssistantError("Not a valid unit")
+
                     sensor_values.append((entity_id, numeric_state, state))
                     if entity_id in self._state_incorrect:
                         self._state_incorrect.remove(entity_id)
@@ -536,8 +547,21 @@ class SensorGroup(GroupEntity, SensorEntity):
             unit_of_measurements.append(_unit_of_measurement)
 
         # Ensure only valid unit of measurements for the specific device class can be used
-        if (device_class := self.device_class) in UNIT_CONVERTERS and all(
-            x in UNIT_CONVERTERS[device_class].VALID_UNITS for x in unit_of_measurements
+        if (
+            # Test if uom's in device class is convertible
+            (device_class := self.device_class) in UNIT_CONVERTERS
+            and all(
+                uom in UNIT_CONVERTERS[device_class].VALID_UNITS
+                for uom in unit_of_measurements
+            )
+        ) or (
+            # Test if uom's in device class is not convertible
+            device_class
+            and device_class not in UNIT_CONVERTERS
+            and device_class in DEVICE_CLASS_UNITS
+            and all(
+                uom in DEVICE_CLASS_UNITS[device_class] for uom in unit_of_measurements
+            )
         ):
             async_delete_issue(
                 self.hass, DOMAIN, f"{self.entity_id}_uoms_not_matching_device_class"
@@ -546,6 +570,7 @@ class SensorGroup(GroupEntity, SensorEntity):
                 self.hass, DOMAIN, f"{self.entity_id}_uoms_not_matching_no_device_class"
             )
             return unit_of_measurements[0]
+
         if device_class:
             async_create_issue(
                 self.hass,
@@ -587,5 +612,13 @@ class SensorGroup(GroupEntity, SensorEntity):
         if (
             device_class := self.device_class
         ) in UNIT_CONVERTERS and self.native_unit_of_measurement:
+            self._can_convert = True
             return UNIT_CONVERTERS[device_class].VALID_UNITS
+        if (
+            device_class
+            and (device_class) in DEVICE_CLASS_UNITS
+            and self.native_unit_of_measurement
+        ):
+            valid_uoms: set = DEVICE_CLASS_UNITS[device_class]
+            return valid_uoms
         return set()
diff --git a/tests/components/group/test_sensor.py b/tests/components/group/test_sensor.py
index aa4901e689c..ec6905a500f 100644
--- a/tests/components/group/test_sensor.py
+++ b/tests/components/group/test_sensor.py
@@ -1,4 +1,5 @@
 """The tests for the Group Sensor platform."""
+
 from __future__ import annotations
 
 from math import prod
@@ -27,6 +28,7 @@ from homeassistant.const import (
     ATTR_ENTITY_ID,
     ATTR_ICON,
     ATTR_UNIT_OF_MEASUREMENT,
+    PERCENTAGE,
     SERVICE_RELOAD,
     STATE_UNAVAILABLE,
     STATE_UNKNOWN,
@@ -557,6 +559,90 @@ async def test_sensor_calculated_result_fails_on_uom(hass: HomeAssistant) -> Non
     assert state.attributes.get("unit_of_measurement") == "kWh"
 
 
+async def test_sensor_calculated_properties_not_convertible_device_class(
+    hass: HomeAssistant,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Test the sensor calculating device_class, state_class and unit of measurement when device class not convertible."""
+    config = {
+        SENSOR_DOMAIN: {
+            "platform": GROUP_DOMAIN,
+            "name": "test_sum",
+            "type": "sum",
+            "entities": ["sensor.test_1", "sensor.test_2", "sensor.test_3"],
+            "unique_id": "very_unique_id_sum_sensor",
+        }
+    }
+
+    entity_ids = config["sensor"]["entities"]
+
+    hass.states.async_set(
+        entity_ids[0],
+        VALUES[0],
+        {
+            "device_class": SensorDeviceClass.HUMIDITY,
+            "state_class": SensorStateClass.MEASUREMENT,
+            "unit_of_measurement": PERCENTAGE,
+        },
+    )
+    hass.states.async_set(
+        entity_ids[1],
+        VALUES[1],
+        {
+            "device_class": SensorDeviceClass.HUMIDITY,
+            "state_class": SensorStateClass.MEASUREMENT,
+            "unit_of_measurement": PERCENTAGE,
+        },
+    )
+    hass.states.async_set(
+        entity_ids[2],
+        VALUES[2],
+        {
+            "device_class": SensorDeviceClass.HUMIDITY,
+            "state_class": SensorStateClass.MEASUREMENT,
+            "unit_of_measurement": PERCENTAGE,
+        },
+    )
+    await hass.async_block_till_done()
+
+    assert await async_setup_component(hass, "sensor", config)
+    await hass.async_block_till_done()
+
+    state = hass.states.get("sensor.test_sum")
+    assert state.state == str(sum(VALUES))
+    assert state.attributes.get("device_class") == "humidity"
+    assert state.attributes.get("state_class") == "measurement"
+    assert state.attributes.get("unit_of_measurement") == "%"
+
+    assert (
+        "Unable to use state. Only entities with correct unit of measurement is"
+        " supported when having a device class"
+    ) not in caplog.text
+
+    hass.states.async_set(
+        entity_ids[2],
+        VALUES[2],
+        {
+            "device_class": SensorDeviceClass.HUMIDITY,
+            "state_class": SensorStateClass.MEASUREMENT,
+        },
+    )
+    await hass.async_block_till_done()
+
+    state = hass.states.get("sensor.test_sum")
+    assert state.state == STATE_UNKNOWN
+    assert state.attributes.get("device_class") == "humidity"
+    assert state.attributes.get("state_class") == "measurement"
+    assert state.attributes.get("unit_of_measurement") == "%"
+
+    assert (
+        "Unable to use state. Only entities with correct unit of measurement is"
+        " supported when having a device class, entity sensor.test_3, value 15.3 with"
+        " device class humidity and unit of measurement None excluded from calculation"
+        " in sensor.test_sum"
+    ) in caplog.text
+
+
 async def test_last_sensor(hass: HomeAssistant) -> None:
     """Test the last sensor."""
     config = {