diff --git a/esphome/components/kamstrup_kmp/kamstrup_kmp.cpp b/esphome/components/kamstrup_kmp/kamstrup_kmp.cpp
index 9f2557243c..9bebd4cd56 100644
--- a/esphome/components/kamstrup_kmp/kamstrup_kmp.cpp
+++ b/esphome/components/kamstrup_kmp/kamstrup_kmp.cpp
@@ -139,12 +139,12 @@ void KamstrupKMPComponent::clear_uart_rx_buffer_() {
 
 void KamstrupKMPComponent::read_command_(uint16_t command) {
   uint8_t buffer[20] = {0};
-  int buffer_len = 0;
+  size_t buffer_len = 0;
   int data;
   int timeout = 250;  // ms
 
   // Read the data from the UART
-  while (timeout > 0 && buffer_len < static_cast<int>(sizeof(buffer))) {
+  while (timeout > 0 && buffer_len < sizeof(buffer)) {
     if (this->available()) {
       data = this->read();
       if (data > -1) {
@@ -183,7 +183,7 @@ void KamstrupKMPComponent::read_command_(uint16_t command) {
   // Decode
   uint8_t msg[20] = {0};
   int msg_len = 0;
-  for (int i = 1; i < buffer_len - 1; i++) {
+  for (size_t i = 1; i < buffer_len - 1; i++) {
     if (buffer[i] == 0x1B) {
       msg[msg_len++] = buffer[i + 1] ^ 0xFF;
       i++;
diff --git a/esphome/components/toshiba/toshiba.cpp b/esphome/components/toshiba/toshiba.cpp
index 53114cc50f..a23b4c7cc3 100644
--- a/esphome/components/toshiba/toshiba.cpp
+++ b/esphome/components/toshiba/toshiba.cpp
@@ -275,7 +275,7 @@ static Ras2819tSecondPacketCodes get_ras_2819t_second_packet_codes(climate::Clim
  */
 static uint8_t get_ras_2819t_temp_code(float temperature) {
   int temp_index = static_cast<int>(temperature) - 18;
-  if (temp_index < 0 || temp_index >= static_cast<int>(sizeof(RAS_2819T_TEMP_CODES))) {
+  if (temp_index < 0 || static_cast<size_t>(temp_index) >= sizeof(RAS_2819T_TEMP_CODES)) {
     ESP_LOGW(TAG, "Temperature %.1f°C out of range [18-30°C], defaulting to 24°C", temperature);
     return 0x40;  // Default to 24°C
   }