diff --git a/index.html b/index.html
index 1355ab8..7e30fad 100644
--- a/index.html
+++ b/index.html
@@ -166,8 +166,8 @@ input[type=file]{display:none}
         <option>Футбол</option>
         <option>Хоккей на траве</option>
       </select>>
-      <input type="number" id="regAge" placeholder="Возраст" min="5" max="100">
-      <input type="date" id="regBirth" placeholder="Дата рождения">
+      <input type="number" id="regAge" placeholder="Возраст (авто)" min="5" max="100" readonly style="background:var(--gray-100)">
+      <input type="date" id="regBirth" placeholder="Дата рождения" onchange="calcAge()">
     </div>
     <input type="text" id="regClub" placeholder="Клуб / спортивная школа">
     <div class="grid2">
@@ -395,6 +395,17 @@ function registerProfile() {
   loginProfile(profile.id);
 }
 
+function calcAge() {
+  const b = document.getElementById('regBirth').value;
+  if (!b) return;
+  const birth = new Date(b);
+  const today = new Date();
+  let age = today.getFullYear() - birth.getFullYear();
+  const m = today.getMonth() - birth.getMonth();
+  if (m < 0 || (m === 0 && today.getDate() < birth.getDate())) age--;
+  document.getElementById('regAge').value = age;
+}
+
 function previewRegPhoto() {
   const f = document.getElementById('regPhoto').files[0];
   if (!f) return;