diff --git a/apps/myprofile/README.md b/apps/myprofile/README.md
index 4b2fac9f3..6879d84fc 100644
--- a/apps/myprofile/README.md
+++ b/apps/myprofile/README.md
@@ -4,12 +4,14 @@ Configure your personal profile. All settings are optional and are only stored o
 
 ## Available settings
 
-| Setting       | Description                     | Displayed in        | Stored in | Default value | How to measure                                                    |
-| ------------- | ------------------------------- | ------------------- | --------- | ------------- | ----------------------------------------------------------------- |
-| HR max        | maximum heart rate              | BPM                 | BPM       | 60            | Use maximum value when exercising.<br/> If unsure set to 220-age. |
-| HR min        | minimum heart rate              | BPM                 | BPM       | 200           | Measure your heart rate after waking up                           |
-| Stride length | distance traveled with one step | local length unit   | meter     | 0 (=not set)  | Walk 10 steps and divide the travelled distance by 10             |
+| Setting       | Description                     | Displayed in        | Stored in    | Default value | How to measure                                                    |
+| ------------- | ------------------------------- | ------------------- | ------------ | ------------- | ----------------------------------------------------------------- |
+| Birthday      | Used to calculate age           | year, month, day    | 'YYYY-MM-DD' | 01.01.1970    | -                                                                 |
+| HR max        | maximum heart rate              | BPM                 | BPM          | 60            | Use maximum value when exercising.<br/> If unsure set to 220-age. |
+| HR min        | minimum heart rate              | BPM                 | BPM          | 200           | Measure your heart rate after waking up                           |
+| Stride length | distance traveled with one step | local length unit   | meter        | 0 (=not set)  | Walk 10 steps and divide the travelled distance by 10             |
 
 ## Developer notes
 
-Feel free to add additional settings
+- Feel free to add additional settings.
+- For values without reasonable defaults never assume that a value is set. Always check the value before using it.
diff --git a/apps/myprofile/settings.js b/apps/myprofile/settings.js
index 80979bd2c..ba2603d65 100644
--- a/apps/myprofile/settings.js
+++ b/apps/myprofile/settings.js
@@ -5,47 +5,110 @@
     minHrm: 60,
     maxHrm: 200,
     strideLength: 0, // 0 = not set
+    birthday: '1970-01-01',
   }, require('Storage').readJSON(FILE, true) || {});
 
   function writeProfile() {
     require('Storage').writeJSON(FILE, myprofile);
   }
 
-  // Show the menu
-  E.showMenu({
-    "" : { "title" : /*LANG*/"My Profile" },
+  const ageMenu = () => {
+    const date = new Date(myprofile.birthday);
 
-    "< Back" : () => back(),
+    E.showMenu({
+      "" : { "title" : /*LANG*/"Birthday" },
 
-    /*LANG*/'HR max': {
-      format: v => /*LANG*/`${v} BPM`,
-      value: myprofile.maxHrm,
-      min: 30, max: 220,
-      onchange: v => {
-        myprofile.maxHrm = v;
-        writeProfile();
-      }
-    },
-
-    /*LANG*/'HR min': {
-      format: v => /*LANG*/`${v} BPM`,
-      value: myprofile.minHrm,
-      min: 30, max: 220,
-      onchange: v => {
-        myprofile.minHrm = v;
-        writeProfile();
-      }
-    },
-
-    /*LANG*/"Stride length": {
-      value: myprofile.strideLength,
-      min:0.00,
-      step:0.01,
-      format: v => v ? require("locale").distance(v, 2) : '-',
-      onchange: v => {
-        myprofile.strideLength=v;
-        writeProfile();
+      "< Back" : () => {
+        if (date != new Date(myprofile.birthday)) {
+          if (date > new Date()) {
+            E.showPrompt(/*LANG*/"Birthday must not be in future!", {
+              buttons : {"Ok":true},
+            }).then(() => ageMenu());
+          } else {
+            // Birthday changed
+            const age = (new Date()).getFullYear() - date.getFullYear();
+            const newMaxHRM = 220-age;
+            E.showPrompt(/*LANG*/`Set HR max to ${newMaxHRM} calculated from age?`).then(function(v) {
+              myprofile.birthday = date.getFullYear() + "-" + (date.getMonth() + 1).toString().padStart(2, '0') + "-" + date.getDate().toString().padStart(2, '0');
+              if (v) {
+                myprofile.maxHrm = newMaxHRM;
+                writeProfile();
+              }
+              mainMenu();
+            });
+          }
+        } else {
+          mainMenu();
+        }
       },
-    },
-  });
+
+      /*LANG*/"Day": {
+        value: date ? date.getDate() : null,
+        min: 1,
+        max: 31,
+        wrap: true,
+        onchange: v => {
+          date.setDate(v);
+        }
+      },
+      /*LANG*/"Month": {
+        value: date ? date.getMonth() + 1 : null,
+        format: v => require("date_utils").month(v),
+        onchange: v => {
+          date.setMonth((v+11)%12);
+        }
+      },
+      /*LANG*/"Year": {
+        value: date ? date.getFullYear() : null,
+        min: 1900,
+        max: (new Date()).getFullYear(),
+        onchange: v => {
+          date.setFullYear(v);
+        }
+      },
+    });
+  };
+
+  const mainMenu = () => {
+    E.showMenu({
+      "" : { "title" : /*LANG*/"My Profile" },
+
+      "< Back" : () => back(),
+
+      /*LANG*/"Birthday" : () => ageMenu(),
+
+      /*LANG*/'HR max': {
+        format: v => /*LANG*/`${v} BPM`,
+        value: myprofile.maxHrm,
+        min: 30, max: 220,
+        onchange: v => {
+          myprofile.maxHrm = v;
+          writeProfile();
+        }
+      },
+
+      /*LANG*/'HR min': {
+        format: v => /*LANG*/`${v} BPM`,
+        value: myprofile.minHrm,
+        min: 30, max: 220,
+        onchange: v => {
+          myprofile.minHrm = v;
+          writeProfile();
+        }
+      },
+
+      /*LANG*/"Stride length": {
+        value: myprofile.strideLength,
+        min:0.00,
+        step:0.01,
+        format: v => v ? require("locale").distance(v, 2) : '-',
+        onchange: v => {
+          myprofile.strideLength=v;
+          writeProfile();
+        },
+      },
+    });
+  };
+
+  mainMenu();
 })