diff --git a/client/custom/src/views/c-vmh-mietverhaeltnis/fields/warmmiete.js b/client/custom/src/views/c-vmh-mietverhaeltnis/fields/warmmiete.js
new file mode 100644
index 00000000..1ca28e18
--- /dev/null
+++ b/client/custom/src/views/c-vmh-mietverhaeltnis/fields/warmmiete.js
@@ -0,0 +1,38 @@
+define('custom:views/c-vmh-mietverhaeltnis/fields/warmmiete', ['views/fields/currency'], function (Dep) {
+
+    return Dep.extend({
+
+        setup: function () {
+            Dep.prototype.setup.call(this);
+
+            this.calculating = false;
+
+            // Listen to changes on dependent fields
+            this.listenTo(this.model, 'change:kaltmiete', this.calculate.bind(this));
+            this.listenTo(this.model, 'change:bKVorauszahlung', this.calculate.bind(this));
+            this.listenTo(this.model, 'change:bKPauschale', this.calculate.bind(this));
+        },
+
+        afterRender: function () {
+            Dep.prototype.afterRender.call(this);
+            // Don't calculate on initial render - only on changes
+        },
+
+        calculate: function () {
+            if (this.calculating) return;
+            this.calculating = true;
+
+            var kaltmiete = parseFloat(this.model.get('kaltmiete')) || 0;
+            var bKVorauszahlung = parseFloat(this.model.get('bKVorauszahlung')) || 0;
+            var bKPauschale = parseFloat(this.model.get('bKPauschale')) || 0;
+
+            var warmmiete = kaltmiete + bKVorauszahlung + bKPauschale;
+
+            // Set value - this will trigger the parent view to update
+            this.model.set('warmmiete', warmmiete);
+
+            this.calculating = false;
+        }
+
+    });
+});
diff --git a/custom/Espo/Custom/Resources/metadata/entityDefs/CVmhMietverhltnis.json b/custom/Espo/Custom/Resources/metadata/entityDefs/CVmhMietverhltnis.json
index f2ab8020..45b642d2 100644
--- a/custom/Espo/Custom/Resources/metadata/entityDefs/CVmhMietverhltnis.json
+++ b/custom/Espo/Custom/Resources/metadata/entityDefs/CVmhMietverhltnis.json
@@ -169,7 +169,8 @@
             "isCustom": true,
             "readOnly": true,
             "required": false,
-            "tooltip": true
+            "tooltip": true,
+            "view": "custom:views/c-vmh-mietverhaeltnis/fields/warmmiete"
         },
         "vmhMietobjekt": {
             "type": "link",
diff --git a/custom/Espo/Custom/Resources/metadata/formula/CVmhMietverhltnis.json b/custom/Espo/Custom/Resources/metadata/formula/CVmhMietverhltnis.json
new file mode 100644
index 00000000..be4b3e20
--- /dev/null
+++ b/custom/Espo/Custom/Resources/metadata/formula/CVmhMietverhltnis.json
@@ -0,0 +1,3 @@
+{
+    "beforeSaveCustomScript": "warmmiete = (kaltmiete ?? 0) + (bKVorauszahlung ?? 0) + (bKPauschale ?? 0);"
+}
diff --git a/data/config.php b/data/config.php
index 9938961a..16c2683a 100644
--- a/data/config.php
+++ b/data/config.php
@@ -359,8 +359,8 @@ return [
     0 => 'youtube.com',
     1 => 'google.com'
   ],
-  'cacheTimestamp' => 1769206320,
-  'microtime' => 1769206320.164239,
+  'cacheTimestamp' => 1769206439,
+  'microtime' => 1769206439.346976,
   'siteUrl' => 'https://crm.bitbylaw.com',
   'fullTextSearchMinLength' => 4,
   'appTimestamp' => 1768843902,