diff --git a/esphome/components/adc/adc_sensor.cpp b/esphome/components/adc/adc_sensor.cpp
index ca87c8d11f..daa1d3c5cf 100644
--- a/esphome/components/adc/adc_sensor.cpp
+++ b/esphome/components/adc/adc_sensor.cpp
@@ -15,10 +15,21 @@ namespace esphome {
 namespace adc {
 
 static const char *const TAG = "adc";
-// 13 bits for S3 / 12 bit for all other esp32 variants
-// create a const to avoid the repated cast to enum
+
+// 13bit for S2, and 12bit for all other esp32 variants
 #ifdef USE_ESP32
 static const adc_bits_width_t ADC_WIDTH_MAX_SOC_BITS = static_cast<adc_bits_width_t>(ADC_WIDTH_MAX - 1);
+
+#ifndef SOC_ADC_RTC_MAX_BITWIDTH
+#if USE_ESP32_VARIANT_ESP32S2
+static const int SOC_ADC_RTC_MAX_BITWIDTH = 13;
+#else
+static const int SOC_ADC_RTC_MAX_BITWIDTH = 12;
+#endif
+#endif
+
+static const int ADC_MAX = (1 << SOC_ADC_RTC_MAX_BITWIDTH) - 1;    // 4095 (12 bit) or 8191 (13 bit)
+static const int ADC_HALF = (1 << SOC_ADC_RTC_MAX_BITWIDTH) >> 1;  // 2048 (12 bit) or 4096 (13 bit)
 #endif
 
 void ADCSensor::setup() {
@@ -75,16 +86,16 @@ void ADCSensor::dump_config() {
   } else {
     switch (this->attenuation_) {
       case ADC_ATTEN_DB_0:
-        ESP_LOGCONFIG(TAG, " Attenuation: 0db (max 1.1V)");
+        ESP_LOGCONFIG(TAG, " Attenuation: 0db");
         break;
       case ADC_ATTEN_DB_2_5:
-        ESP_LOGCONFIG(TAG, " Attenuation: 2.5db (max 1.5V)");
+        ESP_LOGCONFIG(TAG, " Attenuation: 2.5db");
         break;
       case ADC_ATTEN_DB_6:
-        ESP_LOGCONFIG(TAG, " Attenuation: 6db (max 2.2V)");
+        ESP_LOGCONFIG(TAG, " Attenuation: 6db");
         break;
       case ADC_ATTEN_DB_11:
-        ESP_LOGCONFIG(TAG, " Attenuation: 11db (max 3.9V)");
+        ESP_LOGCONFIG(TAG, " Attenuation: 11db");
         break;
       default:  // This is to satisfy the unused ADC_ATTEN_MAX
         break;
@@ -129,16 +140,16 @@ float ADCSensor::sample() {
     return mv / 1000.0f;
   }
 
-  int raw11, raw6 = 4095, raw2 = 4095, raw0 = 4095;
+  int raw11, raw6 = ADC_MAX, raw2 = ADC_MAX, raw0 = ADC_MAX;
   adc1_config_channel_atten(channel_, ADC_ATTEN_DB_11);
   raw11 = adc1_get_raw(channel_);
-  if (raw11 < 4095) {
+  if (raw11 < ADC_MAX) {
     adc1_config_channel_atten(channel_, ADC_ATTEN_DB_6);
     raw6 = adc1_get_raw(channel_);
-    if (raw6 < 4095) {
+    if (raw6 < ADC_MAX) {
       adc1_config_channel_atten(channel_, ADC_ATTEN_DB_2_5);
       raw2 = adc1_get_raw(channel_);
-      if (raw2 < 4095) {
+      if (raw2 < ADC_MAX) {
         adc1_config_channel_atten(channel_, ADC_ATTEN_DB_0);
         raw0 = adc1_get_raw(channel_);
       }
@@ -154,15 +165,15 @@ float ADCSensor::sample() {
   uint32_t mv2 = esp_adc_cal_raw_to_voltage(raw2, &cal_characteristics_[(int) ADC_ATTEN_DB_2_5]);
   uint32_t mv0 = esp_adc_cal_raw_to_voltage(raw0, &cal_characteristics_[(int) ADC_ATTEN_DB_0]);
 
-  // Contribution of each value, in range 0-2048
-  uint32_t c11 = std::min(raw11, 2048);
-  uint32_t c6 = 2048 - std::abs(raw6 - 2048);
-  uint32_t c2 = 2048 - std::abs(raw2 - 2048);
-  uint32_t c0 = std::min(4095 - raw0, 2048);
-  // max theoretical csum value is 2048*4 = 8192
+  // Contribution of each value, in range 0-2048 (12 bit ADC) or 0-4096 (13 bit ADC)
+  uint32_t c11 = std::min(raw11, ADC_HALF);
+  uint32_t c6 = ADC_HALF - std::abs(raw6 - ADC_HALF);
+  uint32_t c2 = ADC_HALF - std::abs(raw2 - ADC_HALF);
+  uint32_t c0 = std::min(ADC_MAX - raw0, ADC_HALF);
+  // max theoretical csum value is 4096*4 = 16384
   uint32_t csum = c11 + c6 + c2 + c0;
 
-  // each mv is max 3900; so max value is 3900*2048*4, fits in unsigned
+  // each mv is max 3900; so max value is 3900*4096*4, fits in unsigned32
   uint32_t mv_scaled = (mv11 * c11) + (mv6 * c6) + (mv2 * c2) + (mv0 * c0);
   return mv_scaled / (float) (csum * 1000U);
 }