diff --git a/homeassistant/components/airgradient/number.py b/homeassistant/components/airgradient/number.py
index 2b7a8bb42d74..e7221e15415b 100644
--- a/homeassistant/components/airgradient/number.py
+++ b/homeassistant/components/airgradient/number.py
@@ -12,7 +12,7 @@ from homeassistant.components.number import (
     NumberEntity,
     NumberEntityDescription,
 )
-from homeassistant.const import PERCENTAGE, EntityCategory
+from homeassistant.const import EntityCategory, UnitOfRatio
 from homeassistant.core import HomeAssistant, callback
 from homeassistant.helpers import entity_registry as er
 from homeassistant.helpers.entity_platform import AddConfigEntryEntitiesCallback
@@ -40,7 +40,7 @@ DISPLAY_BRIGHTNESS = AirGradientNumberEntityDescription(
     native_min_value=0,
     native_max_value=100,
     native_step=1,
-    native_unit_of_measurement=PERCENTAGE,
+    native_unit_of_measurement=UnitOfRatio.PERCENTAGE,
     value_fn=lambda config: config.display_brightness,
     set_value_fn=lambda client, value: client.set_display_brightness(value),
 )
@@ -52,7 +52,7 @@ LED_BAR_BRIGHTNESS = AirGradientNumberEntityDescription(
     native_min_value=0,
     native_max_value=100,
     native_step=1,
-    native_unit_of_measurement=PERCENTAGE,
+    native_unit_of_measurement=UnitOfRatio.PERCENTAGE,
     value_fn=lambda config: config.led_bar_brightness,
     set_value_fn=lambda client, value: client.set_led_bar_brightness(value),
 )
diff --git a/homeassistant/components/airgradient/sensor.py b/homeassistant/components/airgradient/sensor.py
index 010741c8285d..fc1a0e991381 100644
--- a/homeassistant/components/airgradient/sensor.py
+++ b/homeassistant/components/airgradient/sensor.py
@@ -19,11 +19,10 @@ from homeassistant.components.sensor import (
     SensorStateClass,
 )
 from homeassistant.const import (
-    CONCENTRATION_MICROGRAMS_PER_CUBIC_METER,
-    CONCENTRATION_PARTS_PER_MILLION,
-    PERCENTAGE,
     SIGNAL_STRENGTH_DECIBELS_MILLIWATT,
     EntityCategory,
+    UnitOfDensity,
+    UnitOfRatio,
     UnitOfTemperature,
     UnitOfTime,
 )
@@ -57,21 +56,21 @@ MEASUREMENT_SENSOR_TYPES: tuple[AirGradientMeasurementSensorEntityDescription, .
     AirGradientMeasurementSensorEntityDescription(
         key="pm01",
         device_class=SensorDeviceClass.PM1,
-        native_unit_of_measurement=CONCENTRATION_MICROGRAMS_PER_CUBIC_METER,
+        native_unit_of_measurement=UnitOfDensity.MICROGRAMS_PER_CUBIC_METER,
         state_class=SensorStateClass.MEASUREMENT,
         value_fn=lambda status: status.pm01,
     ),
     AirGradientMeasurementSensorEntityDescription(
         key="pm02",
         device_class=SensorDeviceClass.PM25,
-        native_unit_of_measurement=CONCENTRATION_MICROGRAMS_PER_CUBIC_METER,
+        native_unit_of_measurement=UnitOfDensity.MICROGRAMS_PER_CUBIC_METER,
         state_class=SensorStateClass.MEASUREMENT,
         value_fn=lambda status: status.pm02,
     ),
     AirGradientMeasurementSensorEntityDescription(
         key="pm10",
         device_class=SensorDeviceClass.PM10,
-        native_unit_of_measurement=CONCENTRATION_MICROGRAMS_PER_CUBIC_METER,
+        native_unit_of_measurement=UnitOfDensity.MICROGRAMS_PER_CUBIC_METER,
         state_class=SensorStateClass.MEASUREMENT,
         value_fn=lambda status: status.pm10,
     ),
@@ -85,7 +84,7 @@ MEASUREMENT_SENSOR_TYPES: tuple[AirGradientMeasurementSensorEntityDescription, .
     AirGradientMeasurementSensorEntityDescription(
         key="humidity",
         device_class=SensorDeviceClass.HUMIDITY,
-        native_unit_of_measurement=PERCENTAGE,
+        native_unit_of_measurement=UnitOfRatio.PERCENTAGE,
         state_class=SensorStateClass.MEASUREMENT,
         value_fn=lambda status: status.relative_humidity,
     ),
@@ -113,7 +112,7 @@ MEASUREMENT_SENSOR_TYPES: tuple[AirGradientMeasurementSensorEntityDescription, .
     AirGradientMeasurementSensorEntityDescription(
         key="co2",
         device_class=SensorDeviceClass.CO2,
-        native_unit_of_measurement=CONCENTRATION_PARTS_PER_MILLION,
+        native_unit_of_measurement=UnitOfRatio.PERCENTAGE,
         state_class=SensorStateClass.MEASUREMENT,
         value_fn=lambda status: status.rco2,
     ),
@@ -144,7 +143,7 @@ MEASUREMENT_SENSOR_TYPES: tuple[AirGradientMeasurementSensorEntityDescription, .
         key="pm02_raw",
         translation_key="raw_pm02",
         device_class=SensorDeviceClass.PM25,
-        native_unit_of_measurement=CONCENTRATION_MICROGRAMS_PER_CUBIC_METER,
+        native_unit_of_measurement=UnitOfDensity.MICROGRAMS_PER_CUBIC_METER,
         state_class=SensorStateClass.MEASUREMENT,
         entity_registry_enabled_default=False,
         value_fn=lambda status: status.raw_pm02,
@@ -190,7 +189,7 @@ CONFIG_LED_BAR_SENSOR_TYPES: tuple[AirGradientConfigSensorEntityDescription, ...
     AirGradientConfigSensorEntityDescription(
         key="led_bar_brightness",
         translation_key="led_bar_brightness",
-        native_unit_of_measurement=PERCENTAGE,
+        native_unit_of_measurement=UnitOfRatio.PERCENTAGE,
         entity_category=EntityCategory.DIAGNOSTIC,
         value_fn=lambda config: config.led_bar_brightness,
     ),
@@ -216,9 +215,9 @@ CONFIG_DISPLAY_SENSOR_TYPES: tuple[AirGradientConfigSensorEntityDescription, ...
     AirGradientConfigSensorEntityDescription(
         key="display_brightness",
         translation_key="display_brightness",
-        native_unit_of_measurement=PERCENTAGE,
+        native_unit_of_measurement=UnitOfRatio.PERCENTAGE,
         entity_category=EntityCategory.DIAGNOSTIC,
-        value_fn=lambda config: config.display_brightness,
+        value_fn=lambda config: config.led_bar_brightness,
     ),
 )
 
diff --git a/tests/components/airgradient/snapshots/test_number.ambr b/tests/components/airgradient/snapshots/test_number.ambr
index b8c17d7d3f8d..4f1007c975fc 100644
--- a/tests/components/airgradient/snapshots/test_number.ambr
+++ b/tests/components/airgradient/snapshots/test_number.ambr
@@ -38,7 +38,7 @@
     'supported_features': 0,
     'translation_key': 'display_brightness',
     'unique_id': '84fce612f5b8-display_brightness',
-    'unit_of_measurement': '%',
+    'unit_of_measurement': <UnitOfRatio.PERCENTAGE: '%'>,
   })
 # ---
 # name: test_all_entities[number.airgradient_display_brightness-state]
@@ -49,7 +49,7 @@
       <NumberEntityCapabilityAttribute.MIN: 'min'>: 0,
       <NumberEntityCapabilityAttribute.MODE: 'mode'>: <NumberMode.AUTO: 'auto'>,
       <NumberEntityCapabilityAttribute.STEP: 'step'>: 1,
-      <EntityStateAttribute.UNIT_OF_MEASUREMENT: 'unit_of_measurement'>: '%',
+      <EntityStateAttribute.UNIT_OF_MEASUREMENT: 'unit_of_measurement'>: <UnitOfRatio.PERCENTAGE: '%'>,
     }),
     'context': <ANY>,
     'entity_id': 'number.airgradient_display_brightness',
@@ -98,7 +98,7 @@
     'supported_features': 0,
     'translation_key': 'led_bar_brightness',
     'unique_id': '84fce612f5b8-led_bar_brightness',
-    'unit_of_measurement': '%',
+    'unit_of_measurement': <UnitOfRatio.PERCENTAGE: '%'>,
   })
 # ---
 # name: test_all_entities[number.airgradient_led_bar_brightness-state]
@@ -109,7 +109,7 @@
       <NumberEntityCapabilityAttribute.MIN: 'min'>: 0,
       <NumberEntityCapabilityAttribute.MODE: 'mode'>: <NumberMode.AUTO: 'auto'>,
       <NumberEntityCapabilityAttribute.STEP: 'step'>: 1,
-      <EntityStateAttribute.UNIT_OF_MEASUREMENT: 'unit_of_measurement'>: '%',
+      <EntityStateAttribute.UNIT_OF_MEASUREMENT: 'unit_of_measurement'>: <UnitOfRatio.PERCENTAGE: '%'>,
     }),
     'context': <ANY>,
     'entity_id': 'number.airgradient_led_bar_brightness',
diff --git a/tests/components/airgradient/snapshots/test_sensor.ambr b/tests/components/airgradient/snapshots/test_sensor.ambr
index 29ce64fa5d5d..883bd6449f7b 100644
--- a/tests/components/airgradient/snapshots/test_sensor.ambr
+++ b/tests/components/airgradient/snapshots/test_sensor.ambr
@@ -35,7 +35,7 @@
     'supported_features': 0,
     'translation_key': None,
     'unique_id': '84fce612f5b8-co2',
-    'unit_of_measurement': 'ppm',
+    'unit_of_measurement': <UnitOfRatio.PERCENTAGE: '%'>,
   })
 # ---
 # name: test_all_entities[indoor][sensor.airgradient_carbon_dioxide-state]
@@ -44,7 +44,7 @@
       <EntityStateAttribute.DEVICE_CLASS: 'device_class'>: 'carbon_dioxide',
       <EntityStateAttribute.FRIENDLY_NAME: 'friendly_name'>: 'Airgradient Carbon dioxide',
       <SensorEntityCapabilityAttribute.STATE_CLASS: 'state_class'>: <SensorStateClass.MEASUREMENT: 'measurement'>,
-      <EntityStateAttribute.UNIT_OF_MEASUREMENT: 'unit_of_measurement'>: 'ppm',
+      <EntityStateAttribute.UNIT_OF_MEASUREMENT: 'unit_of_measurement'>: <UnitOfRatio.PERCENTAGE: '%'>,
     }),
     'context': <ANY>,
     'entity_id': 'sensor.airgradient_carbon_dioxide',
@@ -143,21 +143,21 @@
     'supported_features': 0,
     'translation_key': 'display_brightness',
     'unique_id': '84fce612f5b8-display_brightness',
-    'unit_of_measurement': '%',
+    'unit_of_measurement': <UnitOfRatio.PERCENTAGE: '%'>,
   })
 # ---
 # name: test_all_entities[indoor][sensor.airgradient_display_brightness-state]
   StateSnapshot({
     'attributes': ReadOnlyDict({
       <EntityStateAttribute.FRIENDLY_NAME: 'friendly_name'>: 'Airgradient Display brightness',
-      <EntityStateAttribute.UNIT_OF_MEASUREMENT: 'unit_of_measurement'>: '%',
+      <EntityStateAttribute.UNIT_OF_MEASUREMENT: 'unit_of_measurement'>: <UnitOfRatio.PERCENTAGE: '%'>,
     }),
     'context': <ANY>,
     'entity_id': 'sensor.airgradient_display_brightness',
     'last_changed': <ANY>,
     'last_reported': <ANY>,
     'last_updated': <ANY>,
-    'state': '0',
+    'state': '100',
   })
 # ---
 # name: test_all_entities[indoor][sensor.airgradient_display_pm_standard-entry]
@@ -316,7 +316,7 @@
     'supported_features': 0,
     'translation_key': None,
     'unique_id': '84fce612f5b8-humidity',
-    'unit_of_measurement': '%',
+    'unit_of_measurement': <UnitOfRatio.PERCENTAGE: '%'>,
   })
 # ---
 # name: test_all_entities[indoor][sensor.airgradient_humidity-state]
@@ -325,7 +325,7 @@
       <EntityStateAttribute.DEVICE_CLASS: 'device_class'>: 'humidity',
       <EntityStateAttribute.FRIENDLY_NAME: 'friendly_name'>: 'Airgradient Humidity',
       <SensorEntityCapabilityAttribute.STATE_CLASS: 'state_class'>: <SensorStateClass.MEASUREMENT: 'measurement'>,
-      <EntityStateAttribute.UNIT_OF_MEASUREMENT: 'unit_of_measurement'>: '%',
+      <EntityStateAttribute.UNIT_OF_MEASUREMENT: 'unit_of_measurement'>: <UnitOfRatio.PERCENTAGE: '%'>,
     }),
     'context': <ANY>,
     'entity_id': 'sensor.airgradient_humidity',
@@ -369,14 +369,14 @@
     'supported_features': 0,
     'translation_key': 'led_bar_brightness',
     'unique_id': '84fce612f5b8-led_bar_brightness',
-    'unit_of_measurement': '%',
+    'unit_of_measurement': <UnitOfRatio.PERCENTAGE: '%'>,
   })
 # ---
 # name: test_all_entities[indoor][sensor.airgradient_led_bar_brightness-state]
   StateSnapshot({
     'attributes': ReadOnlyDict({
       <EntityStateAttribute.FRIENDLY_NAME: 'friendly_name'>: 'Airgradient LED bar brightness',
-      <EntityStateAttribute.UNIT_OF_MEASUREMENT: 'unit_of_measurement'>: '%',
+      <EntityStateAttribute.UNIT_OF_MEASUREMENT: 'unit_of_measurement'>: <UnitOfRatio.PERCENTAGE: '%'>,
     }),
     'context': <ANY>,
     'entity_id': 'sensor.airgradient_led_bar_brightness',
@@ -646,7 +646,7 @@
     'supported_features': 0,
     'translation_key': None,
     'unique_id': '84fce612f5b8-pm01',
-    'unit_of_measurement': 'μg/m³',
+    'unit_of_measurement': <UnitOfDensity.MICROGRAMS_PER_CUBIC_METER: 'μg/m³'>,
   })
 # ---
 # name: test_all_entities[indoor][sensor.airgradient_pm1-state]
@@ -655,7 +655,7 @@
       <EntityStateAttribute.DEVICE_CLASS: 'device_class'>: 'pm1',
       <EntityStateAttribute.FRIENDLY_NAME: 'friendly_name'>: 'Airgradient PM1',
       <SensorEntityCapabilityAttribute.STATE_CLASS: 'state_class'>: <SensorStateClass.MEASUREMENT: 'measurement'>,
-      <EntityStateAttribute.UNIT_OF_MEASUREMENT: 'unit_of_measurement'>: 'μg/m³',
+      <EntityStateAttribute.UNIT_OF_MEASUREMENT: 'unit_of_measurement'>: <UnitOfDensity.MICROGRAMS_PER_CUBIC_METER: 'μg/m³'>,
     }),
     'context': <ANY>,
     'entity_id': 'sensor.airgradient_pm1',
@@ -701,7 +701,7 @@
     'supported_features': 0,
     'translation_key': None,
     'unique_id': '84fce612f5b8-pm10',
-    'unit_of_measurement': 'μg/m³',
+    'unit_of_measurement': <UnitOfDensity.MICROGRAMS_PER_CUBIC_METER: 'μg/m³'>,
   })
 # ---
 # name: test_all_entities[indoor][sensor.airgradient_pm10-state]
@@ -710,7 +710,7 @@
       <EntityStateAttribute.DEVICE_CLASS: 'device_class'>: 'pm10',
       <EntityStateAttribute.FRIENDLY_NAME: 'friendly_name'>: 'Airgradient PM10',
       <SensorEntityCapabilityAttribute.STATE_CLASS: 'state_class'>: <SensorStateClass.MEASUREMENT: 'measurement'>,
-      <EntityStateAttribute.UNIT_OF_MEASUREMENT: 'unit_of_measurement'>: 'μg/m³',
+      <EntityStateAttribute.UNIT_OF_MEASUREMENT: 'unit_of_measurement'>: <UnitOfDensity.MICROGRAMS_PER_CUBIC_METER: 'μg/m³'>,
     }),
     'context': <ANY>,
     'entity_id': 'sensor.airgradient_pm10',
@@ -756,7 +756,7 @@
     'supported_features': 0,
     'translation_key': None,
     'unique_id': '84fce612f5b8-pm02',
-    'unit_of_measurement': 'μg/m³',
+    'unit_of_measurement': <UnitOfDensity.MICROGRAMS_PER_CUBIC_METER: 'μg/m³'>,
   })
 # ---
 # name: test_all_entities[indoor][sensor.airgradient_pm2_5-state]
@@ -765,7 +765,7 @@
       <EntityStateAttribute.DEVICE_CLASS: 'device_class'>: 'pm25',
       <EntityStateAttribute.FRIENDLY_NAME: 'friendly_name'>: 'Airgradient PM2.5',
       <SensorEntityCapabilityAttribute.STATE_CLASS: 'state_class'>: <SensorStateClass.MEASUREMENT: 'measurement'>,
-      <EntityStateAttribute.UNIT_OF_MEASUREMENT: 'unit_of_measurement'>: 'μg/m³',
+      <EntityStateAttribute.UNIT_OF_MEASUREMENT: 'unit_of_measurement'>: <UnitOfDensity.MICROGRAMS_PER_CUBIC_METER: 'μg/m³'>,
     }),
     'context': <ANY>,
     'entity_id': 'sensor.airgradient_pm2_5',
@@ -865,7 +865,7 @@
     'supported_features': 0,
     'translation_key': 'raw_pm02',
     'unique_id': '84fce612f5b8-pm02_raw',
-    'unit_of_measurement': 'μg/m³',
+    'unit_of_measurement': <UnitOfDensity.MICROGRAMS_PER_CUBIC_METER: 'μg/m³'>,
   })
 # ---
 # name: test_all_entities[indoor][sensor.airgradient_raw_pm2_5-state]
@@ -874,7 +874,7 @@
       <EntityStateAttribute.DEVICE_CLASS: 'device_class'>: 'pm25',
       <EntityStateAttribute.FRIENDLY_NAME: 'friendly_name'>: 'Airgradient Raw PM2.5',
       <SensorEntityCapabilityAttribute.STATE_CLASS: 'state_class'>: <SensorStateClass.MEASUREMENT: 'measurement'>,
-      <EntityStateAttribute.UNIT_OF_MEASUREMENT: 'unit_of_measurement'>: 'μg/m³',
+      <EntityStateAttribute.UNIT_OF_MEASUREMENT: 'unit_of_measurement'>: <UnitOfDensity.MICROGRAMS_PER_CUBIC_METER: 'μg/m³'>,
     }),
     'context': <ANY>,
     'entity_id': 'sensor.airgradient_raw_pm2_5',