diff --git a/homeassistant/components/startca/sensor.py b/homeassistant/components/startca/sensor.py
index 50224944849..ab53b039756 100644
--- a/homeassistant/components/startca/sensor.py
+++ b/homeassistant/components/startca/sensor.py
@@ -157,6 +157,13 @@ async def async_setup_platform(
 
     name = config[CONF_NAME]
     monitored_variables = config[CONF_MONITORED_VARIABLES]
+    if bandwidthcap <= 0:
+        monitored_variables = list(
+            filter(
+                lambda itm: itm not in {"limit", "usage", "used_remaining"},
+                monitored_variables,
+            )
+        )
     entities = [
         StartcaSensor(ts_data, name, description)
         for description in SENSOR_TYPES
@@ -193,11 +200,9 @@ class StartcaData:
         self.api_key = api_key
         self.bandwidth_cap = bandwidth_cap
         # Set unlimited users to infinite, otherwise the cap.
-        self.data = (
-            {"limit": self.bandwidth_cap}
-            if self.bandwidth_cap > 0
-            else {"limit": float("inf")}
-        )
+        self.data = {}
+        if self.bandwidth_cap > 0:
+            self.data["limit"] = self.bandwidth_cap
 
     @staticmethod
     def bytes_to_gb(value):
@@ -232,11 +237,9 @@ class StartcaData:
         total_dl = self.bytes_to_gb(xml_data["usage"]["total"]["download"])
         total_ul = self.bytes_to_gb(xml_data["usage"]["total"]["upload"])
 
-        limit = self.data["limit"]
         if self.bandwidth_cap > 0:
             self.data["usage"] = 100 * used_dl / self.bandwidth_cap
-        else:
-            self.data["usage"] = 0
+            self.data["used_remaining"] = self.data["limit"] - used_dl
         self.data["usage_gb"] = used_dl
         self.data["used_download"] = used_dl
         self.data["used_upload"] = used_ul
@@ -246,6 +249,5 @@ class StartcaData:
         self.data["grace_total"] = grace_dl + grace_ul
         self.data["total_download"] = total_dl
         self.data["total_upload"] = total_ul
-        self.data["used_remaining"] = limit - used_dl
 
         return True
diff --git a/tests/components/startca/test_sensor.py b/tests/components/startca/test_sensor.py
index 3907427bbd3..7b691410907 100644
--- a/tests/components/startca/test_sensor.py
+++ b/tests/components/startca/test_sensor.py
@@ -157,18 +157,15 @@ async def test_unlimited_setup(
     await async_setup_component(hass, "sensor", {"sensor": config})
     await hass.async_block_till_done()
 
-    state = hass.states.get("sensor.start_ca_usage_ratio")
-    assert state.attributes.get(ATTR_UNIT_OF_MEASUREMENT) == PERCENTAGE
-    assert state.state == "0"
+    # These sensors should not be created for unlimited setups
+    assert hass.states.get("sensor.start_ca_usage_ratio") is None
+    assert hass.states.get("sensor.start_ca_data_limit") is None
+    assert hass.states.get("sensor.start_ca_remaining") is None
 
     state = hass.states.get("sensor.start_ca_usage")
     assert state.attributes.get(ATTR_UNIT_OF_MEASUREMENT) == UnitOfInformation.GIGABYTES
     assert state.state == "0.0"
 
-    state = hass.states.get("sensor.start_ca_data_limit")
-    assert state.attributes.get(ATTR_UNIT_OF_MEASUREMENT) == UnitOfInformation.GIGABYTES
-    assert state.state == "inf"
-
     state = hass.states.get("sensor.start_ca_used_download")
     assert state.attributes.get(ATTR_UNIT_OF_MEASUREMENT) == UnitOfInformation.GIGABYTES
     assert state.state == "0.0"
@@ -201,10 +198,6 @@ async def test_unlimited_setup(
     assert state.attributes.get(ATTR_UNIT_OF_MEASUREMENT) == UnitOfInformation.GIGABYTES
     assert state.state == "6.48"
 
-    state = hass.states.get("sensor.start_ca_remaining")
-    assert state.attributes.get(ATTR_UNIT_OF_MEASUREMENT) == UnitOfInformation.GIGABYTES
-    assert state.state == "inf"
-
 
 async def test_bad_return_code(
     hass: HomeAssistant, aioclient_mock: AiohttpClientMocker