diff --git a/core/include/kernel_defines.h b/core/include/kernel_defines.h
index df26784ea1..f52830e669 100644
--- a/core/include/kernel_defines.h
+++ b/core/include/kernel_defines.h
@@ -63,6 +63,16 @@ extern "C" {
         ((TYPE *) ((char *) (PTR) - offsetof(TYPE, MEMBER)))
 #endif
 
+/**
+ * @def         index_of(ARRAY, ELEMENT)
+ * @brief       Returns the index of a pointer to an array element.
+
+ * @param[in]   ARRAY    an array
+ * @param[in]   ELEMENT  pointer to an array element
+ * @return      Index of the element in the array
+ */
+#define index_of(ARRAY, ELEMENT) (((uintptr_t)(ELEMENT) - (uintptr_t)(ARRAY)) / sizeof(*(ELEMENT)))
+
 /**
  * @def NORETURN
  * @brief The *NORETURN* keyword tells the compiler to assume that the function
diff --git a/tests/unittests/tests-kernel_defines/tests-kernel_defines.c b/tests/unittests/tests-kernel_defines/tests-kernel_defines.c
index 9714a738df..fc8ac95c03 100644
--- a/tests/unittests/tests-kernel_defines/tests-kernel_defines.c
+++ b/tests/unittests/tests-kernel_defines/tests-kernel_defines.c
@@ -46,10 +46,20 @@ static void test_kernel_version(void)
 #endif
 }
 
+static void test_index_of(void)
+{
+    unsigned foo[8];
+    uint8_t bar[32];
+
+    TEST_ASSERT_EQUAL_INT(5, index_of(foo, &foo[5]));
+    TEST_ASSERT_EQUAL_INT(17, index_of(bar, &bar[17]));
+}
+
 Test *tests_kernel_defines_tests(void)
 {
     EMB_UNIT_TESTFIXTURES(fixtures) {
         new_TestFixture(test_kernel_version),
+        new_TestFixture(test_index_of),
     };
 
     EMB_UNIT_TESTCALLER(kernel_defines_tests, NULL, NULL, fixtures);