diff --git a/ecs.hpp b/ecs.hpp
index cd30ce9..99b683e 100644
--- a/ecs.hpp
+++ b/ecs.hpp
@@ -1086,6 +1086,7 @@ namespace ecs_hpp
 
         template < typename T >
         std::size_t component_count() const noexcept;
+        std::size_t entity_count() const noexcept;
         std::size_t entity_component_count(const const_uentity& ent) const noexcept;
 
         template < typename F >
@@ -1855,6 +1856,10 @@ namespace ecs_hpp
             : 0u;
     }
 
+    inline std::size_t registry::entity_count() const noexcept {
+        return entity_ids_.size();
+    }
+
     inline std::size_t registry::entity_component_count(const const_uentity& ent) const noexcept {
         assert(valid_entity(ent));
         std::size_t component_count = 0u;
diff --git a/ecs_tests.cpp b/ecs_tests.cpp
index 53f3df6..3d00d26 100644
--- a/ecs_tests.cpp
+++ b/ecs_tests.cpp
@@ -411,6 +411,18 @@ TEST_CASE("registry") {
             // entity index overflow
             REQUIRE_THROWS_AS(w.create_entity(), std::logic_error);
         }
+        {
+            ecs::registry w;
+            REQUIRE_FALSE(w.entity_count());
+            auto e1 = w.create_entity();
+            REQUIRE(w.entity_count() == 1u);
+            auto e2 = w.create_entity();
+            REQUIRE(w.entity_count() == 2u);
+            e1.destroy();
+            REQUIRE(w.entity_count() == 1u);
+            e2.destroy();
+            REQUIRE_FALSE(w.entity_count());
+        }
     }
     SECTION("components") {
         {