diff --git a/src/bridge.h b/src/bridge.h
index 0d64dd6012e31..da5a373a0785a 100644
--- a/src/bridge.h
+++ b/src/bridge.h
@@ -65,7 +65,7 @@ bool HasBridgeFlatRamp(Slope tileh, Axis axis);
  */
 inline const BridgeSpec *GetBridgeSpec(BridgeType i)
 {
-	assert(i < lengthof(_bridge));
+	assert(i < std::size(_bridge));
 	return &_bridge[i];
 }
 
diff --git a/src/cargotype.h b/src/cargotype.h
index 10aae014d2aa6..4a7485453e585 100644
--- a/src/cargotype.h
+++ b/src/cargotype.h
@@ -120,7 +120,7 @@ struct CargoSpec {
 	 */
 	static inline size_t GetArraySize()
 	{
-		return lengthof(CargoSpec::array);
+		return std::size(CargoSpec::array);
 	}
 
 	/**
@@ -130,7 +130,7 @@ struct CargoSpec {
 	 */
 	static inline CargoSpec *Get(size_t index)
 	{
-		assert(index < lengthof(CargoSpec::array));
+		assert(index < CargoSpec::GetArraySize());
 		return &CargoSpec::array[index];
 	}
 
diff --git a/src/company_manager_face.h b/src/company_manager_face.h
index dbb11de5fd9ea..61278305200f3 100644
--- a/src/company_manager_face.h
+++ b/src/company_manager_face.h
@@ -83,7 +83,7 @@ static const CompanyManagerFaceBitsInfo _cmf_info[] = {
 	/* CMFV_GLASSES         */ { 31, 1, {  2,  2,  2,  2 }, { 0x347, 0x347, 0x3AE, 0x3AE } }  ///< Depends on CMFV_HAS_GLASSES
 };
 /** Make sure the table's size is right. */
-static_assert(lengthof(_cmf_info) == CMFV_END);
+static_assert(std::size(_cmf_info) == CMFV_END);
 
 /**
  * Gets the company manager's face bits for the given company manager's face variable
diff --git a/src/table/airport_defaults.h b/src/table/airport_defaults.h
index 0a41f7ec8ca86..5927e6d8c32b4 100644
--- a/src/table/airport_defaults.h
+++ b/src/table/airport_defaults.h
@@ -404,7 +404,7 @@ extern const AirportSpec _origin_airport_specs[] = {
 	AS_GENERIC(&_airportfta_oilrig, {}, {}, 1, 1, 0, 4, 0, 0, 0, ATP_TTDP_OILRIG, APC_HELIPORT, STR_NULL, 0, false),
 };
 
-static_assert(NEW_AIRPORT_OFFSET == lengthof(_origin_airport_specs));
+static_assert(NEW_AIRPORT_OFFSET == std::size(_origin_airport_specs));
 
 const AirportSpec AirportSpec::dummy = AS_GENERIC(&_airportfta_dummy, {}, {}, 0, 0, 0, 0, CalendarTime::MIN_YEAR, CalendarTime::MIN_YEAR, 0, ATP_TTDP_LARGE, APC_BEGIN, STR_NULL, 0, false);
 
diff --git a/src/table/airporttiles.h b/src/table/airporttiles.h
index 0393cf7a5f472..6f18f0e8a46d9 100644
--- a/src/table/airporttiles.h
+++ b/src/table/airporttiles.h
@@ -104,7 +104,7 @@ static const AirportTileSpec _origin_airporttile_specs[] = {
 	AT(3, 1), // APT_GRASS_FENCE_NE_FLAG_2
 };
 
-static_assert(NEW_AIRPORTTILE_OFFSET == lengthof(_origin_airporttile_specs));
+static_assert(NEW_AIRPORTTILE_OFFSET == std::size(_origin_airporttile_specs));
 
 #undef AT_NOANIM
 #undef AT
diff --git a/src/table/newgrf_debug_data.h b/src/table/newgrf_debug_data.h
index 1be431a939132..26fec23d7e4db 100644
--- a/src/table/newgrf_debug_data.h
+++ b/src/table/newgrf_debug_data.h
@@ -743,4 +743,4 @@ static const NIFeature * const _nifeatures[] = {
 	&_nif_roadstop,     // GSF_ROADSTOPS
 	&_nif_town,         // GSF_FAKE_TOWNS
 };
-static_assert(lengthof(_nifeatures) == GSF_FAKE_END);
+static_assert(std::size(_nifeatures) == GSF_FAKE_END);
diff --git a/src/table/pricebase.h b/src/table/pricebase.h
index 27af6a370ed26..5e6599d438606 100644
--- a/src/table/pricebase.h
+++ b/src/table/pricebase.h
@@ -80,4 +80,4 @@ extern const PriceBaseSpec _price_base_specs[] = {
 	{    100, PCAT_RUNNING,      GSF_END,          PR_STATION_VALUE      }, ///< PR_INFRASTRUCTURE_STATION
 	{   5000, PCAT_RUNNING,      GSF_END,          PR_BUILD_STATION_AIRPORT}, ///< PR_INFRASTRUCTURE_AIRPORT
 };
-static_assert(lengthof(_price_base_specs) == PR_END);
+static_assert(std::size(_price_base_specs) == PR_END);
diff --git a/src/table/station_land.h b/src/table/station_land.h
index fc47de8d77810..1053cca21a2a2 100644
--- a/src/table/station_land.h
+++ b/src/table/station_land.h
@@ -1011,7 +1011,7 @@ static const DrawTileSprites _station_display_datas_waypoint[] = {
 
 /* Default waypoint is also drawn as fallback for NewGRF waypoints.
  * As these are drawn/build like stations, they may use the same number of layouts. */
-static_assert(lengthof(_station_display_datas_rail) == lengthof(_station_display_datas_waypoint));
+static_assert(std::size(_station_display_datas_rail) == std::size(_station_display_datas_waypoint));
 
 static const DrawTileSprites * const _station_display_datas[] = {
 	_station_display_datas_rail,
diff --git a/src/table/town_land.h b/src/table/town_land.h
index 586a94b3a8fe0..92d09cb770741 100644
--- a/src/table/town_land.h
+++ b/src/table/town_land.h
@@ -1788,7 +1788,7 @@ static const DrawBuildingsTileStruct _town_draw_tile_data[] = {
 };
 #undef M
 /** Make sure we have the right number of elements: 4 variants * 4 build stages for each house */
-static_assert(lengthof(_town_draw_tile_data) == (NEW_HOUSE_OFFSET) * 4 * 4);
+static_assert(std::size(_town_draw_tile_data) == (NEW_HOUSE_OFFSET) * 4 * 4);
 
 /**
  * Describes the data that defines each house in the game
@@ -2277,4 +2277,4 @@ extern const HouseSpec _original_house_specs[] = {
 #undef MS
 
 /** Make sure we have the right number of elements: one entry for each house */
-static_assert(lengthof(_original_house_specs) == NEW_HOUSE_OFFSET);
+static_assert(std::size(_original_house_specs) == NEW_HOUSE_OFFSET);
diff --git a/src/table/train_sprites.h b/src/table/train_sprites.h
index 36dfba17859fb..e4e2b32b75a28 100644
--- a/src/table/train_sprites.h
+++ b/src/table/train_sprites.h
@@ -63,6 +63,6 @@ static const uint8_t _wagon_full_adder[] = {
 	32, 32
 };
 
-static_assert(lengthof(_engine_sprite_base) == lengthof(_engine_sprite_and));
-static_assert(lengthof(_engine_sprite_base) == lengthof(_engine_sprite_add));
-static_assert(lengthof(_engine_sprite_base) == lengthof(_wagon_full_adder));
+static_assert(std::size(_engine_sprite_base) == std::size(_engine_sprite_and));
+static_assert(std::size(_engine_sprite_base) == std::size(_engine_sprite_add));
+static_assert(std::size(_engine_sprite_base) == std::size(_wagon_full_adder));