diff --git a/backend/routers/causal_lab.py b/backend/routers/causal_lab.py
index 372b4a1..1a182a8 100644
--- a/backend/routers/causal_lab.py
+++ b/backend/routers/causal_lab.py
@@ -903,6 +903,8 @@ def analyze_event(body: AnalyzeRequest):
                     inputs[input_id] = round(raw, 4)
             elif src == "surprise" and event.get("surprise_pct") is not None:
                 raw = float(event["surprise_pct"])
+                if cfg.get("normalize"):
+                    raw = raw / 100
                 node_range = cfg.get("range")
                 if node_range and len(node_range) == 2:
                     lo, hi = float(node_range[0]), float(node_range[1])
@@ -1224,19 +1226,15 @@ def _run_auto_analysis(event: dict, template_id: int) -> dict:
                         pass
                 if sp is not None:
                     raw = float(sp)
+                    # normalize:true in node cfg → divide by 100 (coefficients calibrated for fraction)
+                    if cfg.get("normalize"):
+                        raw = raw / 100
                     node_range = cfg.get("range")
-                    if src == "surprise_bps":
-                        if node_range and len(node_range) == 2:
-                            lo, hi = float(node_range[0]), float(node_range[1])
-                            inputs[input_id] = round(max(lo, min(hi, raw)), 4)
-                        else:
-                            inputs[input_id] = round(raw, 4)
+                    if node_range and len(node_range) == 2:
+                        lo, hi = float(node_range[0]), float(node_range[1])
+                        inputs[input_id] = round(max(lo, min(hi, raw)), 4)
                     else:
-                        if node_range and len(node_range) == 2:
-                            lo, hi = float(node_range[0]), float(node_range[1])
-                            inputs[input_id] = round(max(lo, min(hi, raw)), 4)
-                        else:
-                            inputs[input_id] = round(raw, 4)
+                        inputs[input_id] = round(raw, 4)
 
             elif src == "impact_score_scaled" and event.get("impact_score") is not None:
                 inputs[input_id] = float(event["impact_score"]) / 10.0
diff --git a/frontend/src/pages/CausalLab.tsx b/frontend/src/pages/CausalLab.tsx
index 8f5b817..acd6eec 100644
--- a/frontend/src/pages/CausalLab.tsx
+++ b/frontend/src/pages/CausalLab.tsx
@@ -34,6 +34,7 @@ interface InputMapping {
   field?: string
   unit?: string
   range?: number[]
+  normalize?: boolean
 }
 interface DataSources {
   prices:       { key: string; label: string }[]
@@ -1598,6 +1599,15 @@ function TabEditor({ initialId }: { initialId?: number | null }) {
                   </select>
                 </div>
               </>)}
+              {/* Normalisation /100 — visible uniquement pour sources surprise */}
+              {mapping.source === 'surprise' && (
+                <label className="flex items-center gap-2 cursor-pointer mt-1">
+                  <input type="checkbox" checked={!!mapping.normalize}
+                    onChange={e => updateMapping({ normalize: e.target.checked })}
+                    className="accent-cyan-500" />
+                  <span className="text-xs text-slate-400">Normaliser ÷100 <span className="text-slate-600">(coefs calibrés en fraction, pas en %)</span></span>
+                </label>
+              )}
             </div>
           )
         })()}