diff --git a/src/app/components/generic-calculator/calculator.component.ts b/src/app/components/generic-calculator/calculator.component.ts
index 6e9adab4247b3de1d10832835a83c3653edb5521..789305b9a752777438355337e8e700c0dada3eb0 100644
--- a/src/app/components/generic-calculator/calculator.component.ts
+++ b/src/app/components/generic-calculator/calculator.component.ts
@@ -438,7 +438,7 @@ export class GenericCalculatorComponent implements OnInit, DoCheck, AfterViewChe
      */
     private updateUIValidity() {
         this._isUIValid = false;
-
+        if (! this._formulaire.calculateDisabled) {
         if (this._fieldsetComponents !== undefined) {
             this._isUIValid = this._fieldsetComponents.reduce(
                 // callback
@@ -481,6 +481,7 @@ export class GenericCalculatorComponent implements OnInit, DoCheck, AfterViewChe
             this._isUIValid = this._isUIValid && this._pabTableComponent.isValid;
         }
     }
+    }
 
     public getElementStyleDisplay(id: string) {
         const isDisplayed: boolean = this._formulaire.isDisplayed(id);
diff --git a/src/app/formulaire/definition/form-definition.ts b/src/app/formulaire/definition/form-definition.ts
index 4c55719f1a82e22c8d56bb45eda119bf37d97ca5..d2802bd02d1b0b26efd94842c8b553df102c102a 100644
--- a/src/app/formulaire/definition/form-definition.ts
+++ b/src/app/formulaire/definition/form-definition.ts
@@ -45,6 +45,9 @@ export abstract class FormulaireDefinition extends FormulaireNode implements Obs
     /** aide en ligne pour les résultats */
     protected _resultsHelpLinks: { [key: string]: string };
 
+    /** set to true to definitely gray-out Calculate button  */
+    protected _calculateDisabled = false;
+
     /** fichier de configuration */
     private _jsonConfig: {};
 
@@ -71,6 +74,10 @@ export abstract class FormulaireDefinition extends FormulaireNode implements Obs
         }
     }
 
+    public get calculateDisabled(): boolean {
+        return this._calculateDisabled;
+    }
+
     public get specificLocalisation() {
         return this._specificLocalisation;
     }
@@ -160,6 +167,9 @@ export abstract class FormulaireDefinition extends FormulaireNode implements Obs
         }
         this._helpLink = json["help"];
         this._resultsHelpLinks = json["resultsHelp"];
+        if (json["calculateDisabled"] !== undefined) {
+            this._calculateDisabled = json["calculateDisabled"];
+        }
     }
 
     /** called at the end of parseConfig() */