diff --git a/esphome/components/esphome/ota/ota_esphome.cpp b/esphome/components/esphome/ota/ota_esphome.cpp
index 569268ea15..b85d660272 100644
--- a/esphome/components/esphome/ota/ota_esphome.cpp
+++ b/esphome/components/esphome/ota/ota_esphome.cpp
@@ -281,19 +281,15 @@ void ESPHomeOTAComponent::handle_data_() {
 #endif
 
   // Acknowledge auth OK - 1 byte
-  buf[0] = ota::OTA_RESPONSE_AUTH_OK;
-  this->writeall_(buf, 1);
+  this->write_byte_(ota::OTA_RESPONSE_AUTH_OK);
 
   // Read size, 4 bytes MSB first
   if (!this->readall_(buf, 4)) {
     this->log_read_error_(LOG_STR("size"));
     goto error;  // NOLINT(cppcoreguidelines-avoid-goto)
   }
-  ota_size = 0;
-  for (uint8_t i = 0; i < 4; i++) {
-    ota_size <<= 8;
-    ota_size |= buf[i];
-  }
+  ota_size = (static_cast<size_t>(buf[0]) << 24) | (static_cast<size_t>(buf[1]) << 16) |
+             (static_cast<size_t>(buf[2]) << 8) | buf[3];
   ESP_LOGV(TAG, "Size is %u bytes", ota_size);
 
   // Now that we've passed authentication and are actually
@@ -313,8 +309,7 @@ void ESPHomeOTAComponent::handle_data_() {
   update_started = true;
 
   // Acknowledge prepare OK - 1 byte
-  buf[0] = ota::OTA_RESPONSE_UPDATE_PREPARE_OK;
-  this->writeall_(buf, 1);
+  this->write_byte_(ota::OTA_RESPONSE_UPDATE_PREPARE_OK);
 
   // Read binary MD5, 32 bytes
   if (!this->readall_(buf, 32)) {
@@ -326,8 +321,7 @@ void ESPHomeOTAComponent::handle_data_() {
   this->backend_->set_update_md5(sbuf);
 
   // Acknowledge MD5 OK - 1 byte
-  buf[0] = ota::OTA_RESPONSE_BIN_MD5_OK;
-  this->writeall_(buf, 1);
+  this->write_byte_(ota::OTA_RESPONSE_BIN_MD5_OK);
 
   while (total < ota_size) {
     // TODO: timeout check
@@ -354,8 +348,7 @@ void ESPHomeOTAComponent::handle_data_() {
     total += read;
 #if USE_OTA_VERSION == 2
     while (size_acknowledged + OTA_BLOCK_SIZE <= total || (total == ota_size && size_acknowledged < ota_size)) {
-      buf[0] = ota::OTA_RESPONSE_CHUNK_OK;
-      this->writeall_(buf, 1);
+      this->write_byte_(ota::OTA_RESPONSE_CHUNK_OK);
       size_acknowledged += OTA_BLOCK_SIZE;
     }
 #endif
@@ -374,8 +367,7 @@ void ESPHomeOTAComponent::handle_data_() {
   }
 
   // Acknowledge receive OK - 1 byte
-  buf[0] = ota::OTA_RESPONSE_RECEIVE_OK;
-  this->writeall_(buf, 1);
+  this->write_byte_(ota::OTA_RESPONSE_RECEIVE_OK);
 
   error_code = this->backend_->end();
   if (error_code != ota::OTA_RESPONSE_OK) {
@@ -384,8 +376,7 @@ void ESPHomeOTAComponent::handle_data_() {
   }
 
   // Acknowledge Update end OK - 1 byte
-  buf[0] = ota::OTA_RESPONSE_UPDATE_END_OK;
-  this->writeall_(buf, 1);
+  this->write_byte_(ota::OTA_RESPONSE_UPDATE_END_OK);
 
   // Read ACK
   if (!this->readall_(buf, 1) || buf[0] != ota::OTA_RESPONSE_OK) {
@@ -404,8 +395,7 @@ void ESPHomeOTAComponent::handle_data_() {
   App.safe_reboot();
 
 error:
-  buf[0] = static_cast<uint8_t>(error_code);
-  this->writeall_(buf, 1);
+  this->write_byte_(static_cast<uint8_t>(error_code));
   this->cleanup_connection_();
 
   if (this->backend_ != nullptr && update_started) {
diff --git a/esphome/components/esphome/ota/ota_esphome.h b/esphome/components/esphome/ota/ota_esphome.h
index d4a8410d35..057461e6a4 100644
--- a/esphome/components/esphome/ota/ota_esphome.h
+++ b/esphome/components/esphome/ota/ota_esphome.h
@@ -53,6 +53,7 @@ class ESPHomeOTAComponent : public ota::OTAComponent {
 #endif  // USE_OTA_PASSWORD
   bool readall_(uint8_t *buf, size_t len);
   bool writeall_(const uint8_t *buf, size_t len);
+  inline bool write_byte_(uint8_t byte) { return this->writeall_(&byte, 1); }
 
   bool try_read_(size_t to_read, const LogString *desc);
   bool try_write_(size_t to_write, const LogString *desc);