diff --git a/public/js/calculators.js b/public/js/calculators.js
index 6330988..27c283a 100644
--- a/public/js/calculators.js
+++ b/public/js/calculators.js
@@ -1572,22 +1572,32 @@
     });
 
     // Bhutani 1999 hour-specific risk nomogram — 40th / 75th / 95th
-    // percentile TSB boundaries read from the Stanford Medicine Newborn
-    // Nursery reproduction of the original Figure 2 (Bhutani VK et al.,
-    // Pediatrics 1999;103(1):6-14):
-    //   https://med.stanford.edu/newborns/professional-education/jaundice-and-phototherapy/bhutani-nomogram.html
-    // Uncertainty: ±0.3 mg/dL — source is a rendered graph, not a table.
-    // For phototherapy / exchange decisions use the AAP 2022 tab (verified).
+    // percentile TSB boundaries. Values are a pre-digitized transcription
+    // of the original Figure 2 (Bhutani VK et al., Pediatrics 1999;103(1):6-14),
+    // lifted verbatim from the JS data arrays used by the codingace.net
+    // Bhutani calculator:
+    //   https://codingace.net/health/neonate_bilirubin_bhutani.html
+    // Cross-checked against the AAP 2004 CPG reproduction of the same chart:
+    //   https://staffnet.southernhealth.ca/wp-content/uploads/Bhutani-Nomogram.pdf
+    //   (Reproduced with AAP permission from Pediatrics 2004;114:297-316)
+    // 6-hour granularity through the first 72 h, 12-hour after.
     //
-    // Zone semantics:
-    //   High-risk:         >= 95th percentile
-    //   High-intermediate: 75th-95th
-    //   Low-intermediate:  40th-75th
-    //   Low-risk:          < 40th
+    // Zone semantics (per AAP 2004 reproduction legend):
+    //   High-risk:         TSB >= 95th percentile
+    //   High-intermediate: 75th <= TSB < 95th
+    //   Low-intermediate:  40th <= TSB < 75th
+    //   Low-risk:          TSB < 40th
+    //
+    // Clinical note: this nomogram is for RISK STRATIFICATION only.
+    // For phototherapy/exchange decisions use the AAP 2022 tab
+    // (which supersedes the 2004 treatment thresholds).
     var bhutaniZones = {
-      p95: { 24:8.0,  36:11.5, 48:13.0, 60:14.0, 72:15.0, 84:15.5, 96:16.0, 108:16.5, 120:17.0, 132:17.2, 144:17.5 },
-      p75: { 24:6.5,  36:9.5,  48:11.0, 60:12.0, 72:13.0, 84:13.5, 96:14.0, 108:14.0, 120:14.5, 132:14.5, 144:14.5 },
-      p40: { 24:4.5,  36:7.0,  48:8.5,  60:9.5,  72:10.5, 84:11.0, 96:11.5, 108:12.0, 120:12.0, 132:12.0, 144:12.0 }
+      p95: { 6:6.0,  12:7.2,  18:8.5,  24:9.6,  30:11.2, 36:12.8, 42:13.8, 48:14.8,
+             54:15.6, 60:16.2, 66:16.8, 72:17.4, 84:18.0, 96:18.4, 108:18.8, 120:19.0 },
+      p75: { 6:4.5,  12:5.5,  18:6.6,  24:7.8,  30:9.2,  36:10.6, 42:11.6, 48:12.6,
+             54:13.4, 60:14.0, 66:14.6, 72:15.0, 84:15.4, 96:15.6, 108:15.8, 120:16.0 },
+      p40: { 6:3.0,  12:4.0,  18:5.0,  24:6.2,  30:7.2,  36:8.4,  42:9.2,  48:10.0,
+             54:10.6, 60:11.2, 66:11.8, 72:12.2, 84:12.6, 96:12.8, 108:13.0, 120:13.2 }
     };
 
     document.getElementById('btn-calc-bhutani').addEventListener('click', function() {
@@ -1617,7 +1627,7 @@
           '<div class="calc-result-item"><div class="calc-result-label">75th %ile</div><div class="calc-result-value" style="font-size:16px;color:#f97316;">' + p75.toFixed(1) + '</div><div class="calc-result-sub">High-intermediate</div></div>' +
           '<div class="calc-result-item"><div class="calc-result-label">40th %ile</div><div class="calc-result-value" style="font-size:16px;color:#f59e0b;">' + p40.toFixed(1) + '</div><div class="calc-result-sub">Low-intermediate</div></div>' +
         '</div>' +
-        '<p style="font-size:11px;color:var(--g400);margin:12px 0 0;">Bhutani hour-specific nomogram for infants &ge; 35 weeks GA. Values approximated from the Stanford Medicine Bhutani nomogram (reproduces Bhutani et al., Pediatrics 1999). Uncertainty &plusmn;0.3 mg/dL &mdash; use the AAP 2022 tab for phototherapy decisions.</p>';
+        '<p style="font-size:11px;color:var(--g400);margin:12px 0 0;">Bhutani hour-specific risk nomogram for infants &ge; 35 weeks GA. Digitized values from Bhutani et al., Pediatrics 1999 (cross-checked against the AAP 2004 CPG reproduction). For phototherapy decisions use the AAP 2022 tab.</p>';
 
       // Chart: Bhutani zone curves with patient
       renderBiliChart(hours, tsb, [