diff --git a/CPUwall.sh b/CPUwall.sh
index 0cda5cb..a9dcd2f 100755
--- a/CPUwall.sh
+++ b/CPUwall.sh
@@ -125,8 +125,11 @@ while :; do
       my $sample_s = (($ENV{SAMPLE_MS} || 5000) / 1000);
       my $hold_s = $ENV{HOLD_SEC} || 6;
       my $display_bias_w = defined $ENV{DISPLAY_BIAS_W} ? $ENV{DISPLAY_BIAS_W} : 2.5;
-      my $spread_theta = defined $ENV{THERMAL_SPREAD_C_PER_W} ? $ENV{THERMAL_SPREAD_C_PER_W} : 0.85;
       my $clamshell_factor = defined $ENV{CLAMSHELL_FACTOR} ? $ENV{CLAMSHELL_FACTOR} : 1.08;
+      my $ambient_c = defined $ENV{AMBIENT_C} ? $ENV{AMBIENT_C} : 23;
+      my $idle_offset_c = defined $ENV{IDLE_OFFSET_C} ? $ENV{IDLE_OFFSET_C} : 9;
+      my $cpu_theta = defined $ENV{CPU_THETA_C_PER_W} ? $ENV{CPU_THETA_C_PER_W} : 1.55;
+      my $gpu_theta = defined $ENV{GPU_THETA_C_PER_W} ? $ENV{GPU_THETA_C_PER_W} : 1.35;
 
       print "\e[1;97mCPU WALL\e[0m  sample ${sample_s}s  hold ${hold_s}s\n";
       print "\e[38;5;240m$rule\e[0m\n\n";
@@ -192,11 +195,18 @@ while :; do
         ? ($gpu_power_w + $display_component_w)
         : (defined $gpu_used ? ((0.04 * $gpu_used) + $display_component_w) : undef);
 
-      my $gradient_c = (defined $cpu_hot_w && defined $gpu_zone_w)
-        ? abs($cpu_hot_w - $gpu_zone_w) * $spread_theta * pressure_factor($thermal_state) * $clamshell_factor
+      my $thermal_mult = pressure_factor($thermal_state) * $clamshell_factor;
+      my $cpu_abs_c = defined $cpu_hot_w
+        ? ($ambient_c + $idle_offset_c + ($cpu_hot_w * $cpu_theta * $thermal_mult))
+        : undef;
+      my $gpu_abs_c = defined $gpu_zone_w
+        ? ($ambient_c + $idle_offset_c + ($gpu_zone_w * $gpu_theta * $thermal_mult))
+        : undef;
+      my $gradient_c = (defined $cpu_abs_c && defined $gpu_abs_c)
+        ? abs($cpu_abs_c - $gpu_abs_c)
         : undef;
       my $gradient_side = !defined $gradient_c         ? "insufficient data"
-                        : $cpu_hot_w >= $gpu_zone_w   ? "CPU side hotter"
+                        : $cpu_abs_c >= $gpu_abs_c   ? "CPU side hotter"
                         :                               "GPU/display side hotter";
       my $basis = (defined $cpu_power_w && defined $gpu_power_w) ? "power-based estimate" : "util fallback";
       my $state = defined $thermal_state ? $thermal_state : "n/a";
@@ -205,6 +215,7 @@ while :; do
       print "\e[1;97mTHERMAL ESTIMATE\e[0m\n";
       print "\e[38;5;240m$rule\e[0m\n\n";
       printf "  pressure      \e[38;5;%sm%s\e[0m\n", $state_color, $state;
+      printf "  ambient est   %6.2f C\n", $ambient_c;
       printf "  cpu hotspot   %6.2f W  %s\n", $cpu_hot_w, $cpu_hot_name if defined $cpu_hot_w;
       if (defined $gpu_zone_w) {
         if (defined $gpu_power_w) {
@@ -213,9 +224,13 @@ while :; do
           printf "  gpu zone      %6.2f W  util fallback + display %.2f\n", $gpu_zone_w, $display_component_w;
         }
       }
+      printf "  cpu abs est   %6.2f C\n", $cpu_abs_c if defined $cpu_abs_c;
+      printf "  gpu abs est   %6.2f C\n", $gpu_abs_c if defined $gpu_abs_c;
       printf "  est gradient  %6.2f C  %s\n", $gradient_c, $gradient_side if defined $gradient_c;
       printf "  basis         %s\n", $basis;
-      print  "  note          estimate only, not a sensor temperature\n";
+      printf "  model         idle %.1fC + zone_w * theta * pressure * clamshell\n", $idle_offset_c;
+      printf "  theta         cpu %.2fC/W  gpu %.2fC/W\n", $cpu_theta, $gpu_theta;
+      print  "  note          estimated absolute temps, not sensor readings\n";
     '
   )"
 
diff --git a/GPUwall.sh b/GPUwall.sh
index 46aff69..6b9d819 100755
--- a/GPUwall.sh
+++ b/GPUwall.sh
@@ -119,8 +119,11 @@ while :; do
       my $sample_s = (($ENV{SAMPLE_MS} || 5000) / 1000);
       my $hold_s   = $ENV{HOLD_SEC} || 6;
       my $display_bias_w = defined $ENV{DISPLAY_BIAS_W} ? $ENV{DISPLAY_BIAS_W} : 2.5;
-      my $spread_theta = defined $ENV{THERMAL_SPREAD_C_PER_W} ? $ENV{THERMAL_SPREAD_C_PER_W} : 0.85;
       my $clamshell_factor = defined $ENV{CLAMSHELL_FACTOR} ? $ENV{CLAMSHELL_FACTOR} : 1.08;
+      my $ambient_c = defined $ENV{AMBIENT_C} ? $ENV{AMBIENT_C} : 23;
+      my $idle_offset_c = defined $ENV{IDLE_OFFSET_C} ? $ENV{IDLE_OFFSET_C} : 9;
+      my $cpu_theta = defined $ENV{CPU_THETA_C_PER_W} ? $ENV{CPU_THETA_C_PER_W} : 1.55;
+      my $gpu_theta = defined $ENV{GPU_THETA_C_PER_W} ? $ENV{GPU_THETA_C_PER_W} : 1.35;
 
       print "\e[1;97mGPU WALL\e[0m  sample ${sample_s}s  hold ${hold_s}s\n";
       print "\e[38;5;240m$rule\e[0m\n\n";
@@ -172,11 +175,18 @@ while :; do
         ? ($gpu_power_w + $display_component_w)
         : (defined $used ? ((0.04 * $used) + $display_component_w) : undef);
 
-      my $gradient_c = (defined $cpu_hot_w && defined $gpu_zone_w)
-        ? abs($cpu_hot_w - $gpu_zone_w) * $spread_theta * pressure_factor($thermal_state) * $clamshell_factor
+      my $thermal_mult = pressure_factor($thermal_state) * $clamshell_factor;
+      my $cpu_abs_c = defined $cpu_hot_w
+        ? ($ambient_c + $idle_offset_c + ($cpu_hot_w * $cpu_theta * $thermal_mult))
+        : undef;
+      my $gpu_abs_c = defined $gpu_zone_w
+        ? ($ambient_c + $idle_offset_c + ($gpu_zone_w * $gpu_theta * $thermal_mult))
+        : undef;
+      my $gradient_c = (defined $cpu_abs_c && defined $gpu_abs_c)
+        ? abs($cpu_abs_c - $gpu_abs_c)
         : undef;
       my $gradient_side = !defined $gradient_c         ? "insufficient data"
-                        : $cpu_hot_w >= $gpu_zone_w   ? "CPU side hotter"
+                        : $cpu_abs_c >= $gpu_abs_c   ? "CPU side hotter"
                         :                               "GPU/display side hotter";
       my $basis = (defined $cpu_power_w && defined $gpu_power_w) ? "power-based estimate" : "util fallback";
       my $state = defined $thermal_state ? $thermal_state : "n/a";
@@ -185,6 +195,7 @@ while :; do
       print "\n\e[1;97mTHERMAL ESTIMATE\e[0m\n";
       print "\e[38;5;240m$rule\e[0m\n\n";
       printf "  pressure      \e[38;5;%sm%s\e[0m\n", $state_color, $state;
+      printf "  ambient est   %6.2f C\n", $ambient_c;
       printf "  cpu hotspot   %6.2f W  %s\n", $cpu_hot_w, $cpu_hot_name if defined $cpu_hot_w;
       if (defined $gpu_zone_w) {
         if (defined $gpu_power_w) {
@@ -193,9 +204,13 @@ while :; do
           printf "  gpu zone      %6.2f W  util fallback + display %.2f\n", $gpu_zone_w, $display_component_w;
         }
       }
+      printf "  cpu abs est   %6.2f C\n", $cpu_abs_c if defined $cpu_abs_c;
+      printf "  gpu abs est   %6.2f C\n", $gpu_abs_c if defined $gpu_abs_c;
       printf "  est gradient  %6.2f C  %s\n", $gradient_c, $gradient_side if defined $gradient_c;
       printf "  basis         %s\n", $basis;
-      print  "  note          estimate only, not a sensor temperature\n";
+      printf "  model         idle %.1fC + zone_w * theta * pressure * clamshell\n", $idle_offset_c;
+      printf "  theta         cpu %.2fC/W  gpu %.2fC/W\n", $cpu_theta, $gpu_theta;
+      print  "  note          estimated absolute temps, not sensor readings\n";
     '
   )"
 
diff --git a/Readme.md b/Readme.md
index 3be22c1..af407d6 100644
--- a/Readme.md
+++ b/Readme.md
@@ -29,10 +29,10 @@ SAMPLE_MS=2000 HOLD_SEC=2 ./tmux-wall.sh
 Thermal estimate tuning:
 
 ```bash
-DISPLAY_BIAS_W=2.5 THERMAL_SPREAD_C_PER_W=0.85 CLAMSHELL_FACTOR=1.08 ./tmux-wall.sh
+AMBIENT_C=23 IDLE_OFFSET_C=9 DISPLAY_BIAS_W=2.5 CPU_THETA_C_PER_W=1.55 GPU_THETA_C_PER_W=1.35 CLAMSHELL_FACTOR=1.08 ./tmux-wall.sh
 ```
 
-The thermal section is an estimate derived from `powermetrics` CPU/GPU power and activity plus thermal pressure. It is not a direct temperature sensor reading.
+The thermal section now shows estimated absolute CPU-side and GPU-side temperatures plus the estimated gradient. These values are derived from `powermetrics` CPU/GPU power and activity plus thermal pressure. They are modeled estimates, not direct sensor readings.
 
 If you want to attach to an existing session later:
 
diff --git a/tmux-wall.sh b/tmux-wall.sh
index 3135309..2037a36 100755
--- a/tmux-wall.sh
+++ b/tmux-wall.sh
@@ -9,11 +9,14 @@ script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 sample_ms="${SAMPLE_MS:-5000}"
 hold_sec="${HOLD_SEC:-6}"
 display_bias_w="${DISPLAY_BIAS_W:-}"
-thermal_spread="${THERMAL_SPREAD_C_PER_W:-}"
 clamshell_factor="${CLAMSHELL_FACTOR:-}"
+ambient_c="${AMBIENT_C:-}"
+idle_offset_c="${IDLE_OFFSET_C:-}"
+cpu_theta="${CPU_THETA_C_PER_W:-}"
+gpu_theta="${GPU_THETA_C_PER_W:-}"
 
 if [[ "${EUID}" -ne 0 ]]; then
-  exec sudo --preserve-env=TMUX_SESSION_NAME,TMUX_WINDOW_NAME,TMUX_RECREATE,SAMPLE_MS,HOLD_SEC,DISPLAY_BIAS_W,THERMAL_SPREAD_C_PER_W,CLAMSHELL_FACTOR bash "$0" "$@"
+  exec sudo --preserve-env=TMUX_SESSION_NAME,TMUX_WINDOW_NAME,TMUX_RECREATE,SAMPLE_MS,HOLD_SEC,DISPLAY_BIAS_W,CLAMSHELL_FACTOR,AMBIENT_C,IDLE_OFFSET_C,CPU_THETA_C_PER_W,GPU_THETA_C_PER_W bash "$0" "$@"
 fi
 
 if ! command -v tmux >/dev/null 2>&1; then
@@ -35,12 +38,21 @@ env_prefix="SAMPLE_MS=${sample_ms} HOLD_SEC=${hold_sec}"
 if [[ -n "${display_bias_w}" ]]; then
   env_prefix="${env_prefix} DISPLAY_BIAS_W=${display_bias_w}"
 fi
-if [[ -n "${thermal_spread}" ]]; then
-  env_prefix="${env_prefix} THERMAL_SPREAD_C_PER_W=${thermal_spread}"
-fi
 if [[ -n "${clamshell_factor}" ]]; then
   env_prefix="${env_prefix} CLAMSHELL_FACTOR=${clamshell_factor}"
 fi
+if [[ -n "${ambient_c}" ]]; then
+  env_prefix="${env_prefix} AMBIENT_C=${ambient_c}"
+fi
+if [[ -n "${idle_offset_c}" ]]; then
+  env_prefix="${env_prefix} IDLE_OFFSET_C=${idle_offset_c}"
+fi
+if [[ -n "${cpu_theta}" ]]; then
+  env_prefix="${env_prefix} CPU_THETA_C_PER_W=${cpu_theta}"
+fi
+if [[ -n "${gpu_theta}" ]]; then
+  env_prefix="${env_prefix} GPU_THETA_C_PER_W=${gpu_theta}"
+fi
 
 if tmux has-session -t "${session_name}" 2>/dev/null; then
   if [[ "${recreate_session}" == "1" ]]; then