diff --git a/esphome/components/ld2410/ld2410.cpp b/esphome/components/ld2410/ld2410.cpp
index 608882565f..391f2024cd 100644
--- a/esphome/components/ld2410/ld2410.cpp
+++ b/esphome/components/ld2410/ld2410.cpp
@@ -13,8 +13,6 @@ namespace esphome {
 namespace ld2410 {
 
 static const char *const TAG = "ld2410";
-static const char *const UNKNOWN_MAC = "unknown";
-static const char *const VERSION_FMT = "%u.%02X.%02X%02X%02X%02X";
 
 enum BaudRate : uint8_t {
   BAUD_RATE_9600 = 1,
@@ -181,15 +179,15 @@ static inline bool validate_header_footer(const uint8_t *header_footer, const ui
 }
 
 void LD2410Component::dump_config() {
-  std::string mac_str =
-      mac_address_is_valid(this->mac_address_) ? format_mac_address_pretty(this->mac_address_) : UNKNOWN_MAC;
-  std::string version = str_sprintf(VERSION_FMT, this->version_[1], this->version_[0], this->version_[5],
-                                    this->version_[4], this->version_[3], this->version_[2]);
+  char mac_s[18];
+  char version_s[20];
+  const char *mac_str = ld24xx::format_mac_str(this->mac_address_, mac_s);
+  ld24xx::format_version_str(this->version_, version_s);
   ESP_LOGCONFIG(TAG,
                 "LD2410:\n"
                 "  Firmware version: %s\n"
                 "  MAC address: %s",
-                version.c_str(), mac_str.c_str());
+                version_s, mac_str);
 #ifdef USE_BINARY_SENSOR
   ESP_LOGCONFIG(TAG, "Binary Sensors:");
   LOG_BINARY_SENSOR("  ", "Target", this->target_binary_sensor_);
@@ -448,12 +446,12 @@ bool LD2410Component::handle_ack_data_() {
 
     case CMD_QUERY_VERSION: {
       std::memcpy(this->version_, &this->buffer_data_[12], sizeof(this->version_));
-      std::string version = str_sprintf(VERSION_FMT, this->version_[1], this->version_[0], this->version_[5],
-                                        this->version_[4], this->version_[3], this->version_[2]);
-      ESP_LOGV(TAG, "Firmware version: %s", version.c_str());
+      char version_s[20];
+      ld24xx::format_version_str(this->version_, version_s);
+      ESP_LOGV(TAG, "Firmware version: %s", version_s);
 #ifdef USE_TEXT_SENSOR
       if (this->version_text_sensor_ != nullptr) {
-        this->version_text_sensor_->publish_state(version);
+        this->version_text_sensor_->publish_state(version_s);
       }
 #endif
       break;
@@ -506,9 +504,9 @@ bool LD2410Component::handle_ack_data_() {
         std::memcpy(this->mac_address_, &this->buffer_data_[10], sizeof(this->mac_address_));
       }
 
-      std::string mac_str =
-          mac_address_is_valid(this->mac_address_) ? format_mac_address_pretty(this->mac_address_) : UNKNOWN_MAC;
-      ESP_LOGV(TAG, "MAC address: %s", mac_str.c_str());
+      char mac_s[18];
+      const char *mac_str = ld24xx::format_mac_str(this->mac_address_, mac_s);
+      ESP_LOGV(TAG, "MAC address: %s", mac_str);
 #ifdef USE_TEXT_SENSOR
       if (this->mac_text_sensor_ != nullptr) {
         this->mac_text_sensor_->publish_state(mac_str);
diff --git a/esphome/components/ld2412/ld2412.cpp b/esphome/components/ld2412/ld2412.cpp
index 5323a9a658..4f2fd7c2bd 100644
--- a/esphome/components/ld2412/ld2412.cpp
+++ b/esphome/components/ld2412/ld2412.cpp
@@ -14,8 +14,6 @@ namespace esphome {
 namespace ld2412 {
 
 static const char *const TAG = "ld2412";
-static const char *const UNKNOWN_MAC = "unknown";
-static const char *const VERSION_FMT = "%u.%02X.%02X%02X%02X%02X";
 
 enum BaudRate : uint8_t {
   BAUD_RATE_9600 = 1,
@@ -200,15 +198,15 @@ static inline bool validate_header_footer(const uint8_t *header_footer, const ui
 }
 
 void LD2412Component::dump_config() {
-  std::string mac_str =
-      mac_address_is_valid(this->mac_address_) ? format_mac_address_pretty(this->mac_address_) : UNKNOWN_MAC;
-  std::string version = str_sprintf(VERSION_FMT, this->version_[1], this->version_[0], this->version_[5],
-                                    this->version_[4], this->version_[3], this->version_[2]);
+  char mac_s[18];
+  char version_s[20];
+  const char *mac_str = ld24xx::format_mac_str(this->mac_address_, mac_s);
+  ld24xx::format_version_str(this->version_, version_s);
   ESP_LOGCONFIG(TAG,
                 "LD2412:\n"
                 "  Firmware version: %s\n"
                 "  MAC address: %s",
-                version.c_str(), mac_str.c_str());
+                version_s, mac_str);
 #ifdef USE_BINARY_SENSOR
   ESP_LOGCONFIG(TAG, "Binary Sensors:");
   LOG_BINARY_SENSOR("  ", "DynamicBackgroundCorrectionStatus",
@@ -492,12 +490,12 @@ bool LD2412Component::handle_ack_data_() {
 
     case CMD_QUERY_VERSION: {
       std::memcpy(this->version_, &this->buffer_data_[12], sizeof(this->version_));
-      std::string version = str_sprintf(VERSION_FMT, this->version_[1], this->version_[0], this->version_[5],
-                                        this->version_[4], this->version_[3], this->version_[2]);
-      ESP_LOGV(TAG, "Firmware version: %s", version.c_str());
+      char version_s[20];
+      ld24xx::format_version_str(this->version_, version_s);
+      ESP_LOGV(TAG, "Firmware version: %s", version_s);
 #ifdef USE_TEXT_SENSOR
       if (this->version_text_sensor_ != nullptr) {
-        this->version_text_sensor_->publish_state(version);
+        this->version_text_sensor_->publish_state(version_s);
       }
 #endif
       break;
@@ -544,9 +542,9 @@ bool LD2412Component::handle_ack_data_() {
         std::memcpy(this->mac_address_, &this->buffer_data_[10], sizeof(this->mac_address_));
       }
 
-      std::string mac_str =
-          mac_address_is_valid(this->mac_address_) ? format_mac_address_pretty(this->mac_address_) : UNKNOWN_MAC;
-      ESP_LOGV(TAG, "MAC address: %s", mac_str.c_str());
+      char mac_s[18];
+      const char *mac_str = ld24xx::format_mac_str(this->mac_address_, mac_s);
+      ESP_LOGV(TAG, "MAC address: %s", mac_str);
 #ifdef USE_TEXT_SENSOR
       if (this->mac_text_sensor_ != nullptr) {
         this->mac_text_sensor_->publish_state(mac_str);
diff --git a/esphome/components/ld2450/ld2450.cpp b/esphome/components/ld2450/ld2450.cpp
index c9d4da47a4..8e5287aec7 100644
--- a/esphome/components/ld2450/ld2450.cpp
+++ b/esphome/components/ld2450/ld2450.cpp
@@ -17,8 +17,6 @@ namespace esphome {
 namespace ld2450 {
 
 static const char *const TAG = "ld2450";
-static const char *const UNKNOWN_MAC = "unknown";
-static const char *const VERSION_FMT = "%u.%02X.%02X%02X%02X%02X";
 
 enum BaudRate : uint8_t {
   BAUD_RATE_9600 = 1,
@@ -192,15 +190,15 @@ void LD2450Component::setup() {
 }
 
 void LD2450Component::dump_config() {
-  std::string mac_str =
-      mac_address_is_valid(this->mac_address_) ? format_mac_address_pretty(this->mac_address_) : UNKNOWN_MAC;
-  std::string version = str_sprintf(VERSION_FMT, this->version_[1], this->version_[0], this->version_[5],
-                                    this->version_[4], this->version_[3], this->version_[2]);
+  char mac_s[18];
+  char version_s[20];
+  const char *mac_str = ld24xx::format_mac_str(this->mac_address_, mac_s);
+  ld24xx::format_version_str(this->version_, version_s);
   ESP_LOGCONFIG(TAG,
                 "LD2450:\n"
                 "  Firmware version: %s\n"
                 "  MAC address: %s",
-                version.c_str(), mac_str.c_str());
+                version_s, mac_str);
 #ifdef USE_BINARY_SENSOR
   ESP_LOGCONFIG(TAG, "Binary Sensors:");
   LOG_BINARY_SENSOR("  ", "MovingTarget", this->moving_target_binary_sensor_);
@@ -642,12 +640,12 @@ bool LD2450Component::handle_ack_data_() {
 
     case CMD_QUERY_VERSION: {
       std::memcpy(this->version_, &this->buffer_data_[12], sizeof(this->version_));
-      std::string version = str_sprintf(VERSION_FMT, this->version_[1], this->version_[0], this->version_[5],
-                                        this->version_[4], this->version_[3], this->version_[2]);
-      ESP_LOGV(TAG, "Firmware version: %s", version.c_str());
+      char version_s[20];
+      ld24xx::format_version_str(this->version_, version_s);
+      ESP_LOGV(TAG, "Firmware version: %s", version_s);
 #ifdef USE_TEXT_SENSOR
       if (this->version_text_sensor_ != nullptr) {
-        this->version_text_sensor_->publish_state(version);
+        this->version_text_sensor_->publish_state(version_s);
       }
 #endif
       break;
@@ -663,9 +661,9 @@ bool LD2450Component::handle_ack_data_() {
         std::memcpy(this->mac_address_, &this->buffer_data_[10], sizeof(this->mac_address_));
       }
 
-      std::string mac_str =
-          mac_address_is_valid(this->mac_address_) ? format_mac_address_pretty(this->mac_address_) : UNKNOWN_MAC;
-      ESP_LOGV(TAG, "MAC address: %s", mac_str.c_str());
+      char mac_s[18];
+      const char *mac_str = ld24xx::format_mac_str(this->mac_address_, mac_s);
+      ESP_LOGV(TAG, "MAC address: %s", mac_str);
 #ifdef USE_TEXT_SENSOR
       if (this->mac_text_sensor_ != nullptr) {
         this->mac_text_sensor_->publish_state(mac_str);
diff --git a/esphome/components/ld24xx/ld24xx.h b/esphome/components/ld24xx/ld24xx.h
index 1cd5e01163..e21c05077d 100644
--- a/esphome/components/ld24xx/ld24xx.h
+++ b/esphome/components/ld24xx/ld24xx.h
@@ -1,8 +1,10 @@
 #pragma once
 
 #include "esphome/core/defines.h"
+#include "esphome/core/helpers.h"
 
 #include <memory>
+#include <span>
 
 #ifdef USE_SENSOR
 #include "esphome/core/helpers.h"
@@ -39,6 +41,27 @@
 namespace esphome {
 namespace ld24xx {
 
+static const char *const UNKNOWN_MAC = "unknown";
+static const char *const VERSION_FMT = "%u.%02X.%02X%02X%02X%02X";
+
+// Helper function to format MAC address with stack allocation
+// Returns pointer to UNKNOWN_MAC constant or formatted buffer
+// Buffer must be exactly 18 bytes (17 for "XX:XX:XX:XX:XX:XX" + null terminator)
+inline const char *format_mac_str(const uint8_t *mac_address, std::span<char, 18> buffer) {
+  if (mac_address_is_valid(mac_address)) {
+    format_mac_addr_upper(mac_address, buffer.data());
+    return buffer.data();
+  }
+  return UNKNOWN_MAC;
+}
+
+// Helper function to format firmware version with stack allocation
+// Buffer must be exactly 20 bytes (format: "x.xxXXXXXX" fits in 11 + null terminator, 20 for safety)
+inline void format_version_str(const uint8_t *version, std::span<char, 20> buffer) {
+  snprintf(buffer.data(), buffer.size(), VERSION_FMT, version[1], version[0], version[5], version[4], version[3],
+           version[2]);
+}
+
 #ifdef USE_SENSOR
 // Helper class to store a sensor with a deduplicator & publish state only when the value changes
 template<typename T> class SensorWithDedup {