diff --git a/README.md b/README.md
index 73ff5c6..5667aa1 100644
--- a/README.md
+++ b/README.md
@@ -8,6 +8,7 @@ A simple habit tracker that runs entirely in your web browser. No installation,
 - **Check them off** – click **Mark done today** each day you do the habit. Click it again to undo.
 - **See your streak** – each habit shows how many days in a row you've kept it up. If you haven't checked it off yet today, your streak from yesterday still counts until the day is over.
 - **30-day grid** – a row of squares shows the last 30 days (oldest on the left, today on the right). Green means done. Click any square to fix a day you forgot to mark.
+- **Weekly summary** – a "This week" box at the top shows how many days each habit was done so far this week (for example "4 of 7 days"), with a bar to compare at a glance. The week starts on the usual day for your region (Sunday or Monday) and resets automatically.
 - **Rename or delete** habits with the buttons next to each one.
 
 ## How to start it
diff --git a/index.html b/index.html
index f41dc85..830b75d 100644
--- a/index.html
+++ b/index.html
@@ -138,6 +138,33 @@
     font-size: 0.8rem;
     margin-top: 4px;
   }
+  .week-summary {
+    background: var(--card);
+    border: 1px solid var(--border);
+    border-radius: 12px;
+    padding: 16px;
+    margin-bottom: 20px;
+  }
+  .week-summary h2 { margin: 0; font-size: 1.15rem; }
+  .week-range { color: var(--muted); font-size: 0.9rem; margin: 2px 0 12px; }
+  .week-row {
+    display: grid;
+    grid-template-columns: minmax(80px, 1.2fr) 2fr auto;
+    align-items: center;
+    gap: 12px;
+    padding: 6px 0;
+  }
+  .week-row + .week-row { border-top: 1px solid var(--border); }
+  .week-name { font-weight: 600; word-break: break-word; }
+  .week-bar {
+    height: 10px;
+    border-radius: 5px;
+    background: var(--empty);
+    overflow: hidden;
+  }
+  .week-bar-fill { height: 100%; background: var(--accent); border-radius: 5px; }
+  .week-count { color: var(--muted); font-size: 0.95rem; white-space: nowrap; }
+  .week-count strong { color: var(--text); }
   .hint {
     color: var(--muted);
     font-size: 0.85rem;
@@ -160,6 +187,8 @@
     <button type="submit" class="primary">Add habit</button>
   </form>
 
+  <section class="week-summary" id="weekSummary" hidden></section>
+
   <div id="habitList"></div>
 
   <p class="hint">Tip: click any square in the 30-day grid to mark or unmark that day.
@@ -234,6 +263,28 @@
     }
     return count;
   }
+  // First day of the week for the user's region (0 = Sunday, 1 = Monday, ...).
+  // Uses the browser's regional settings when available, otherwise Monday.
+  function weekStartDay() {
+    try {
+      var loc = new Intl.Locale(navigator.language || "en");
+      var info = typeof loc.getWeekInfo === "function" ? loc.getWeekInfo() : loc.weekInfo;
+      if (info && info.firstDay >= 1 && info.firstDay <= 7) return info.firstDay % 7;
+    } catch (e) { /* fall through */ }
+    return 1;
+  }
+  var WEEK_START = weekStartDay();
+  // How many days of the current week have passed, counting today (1-7).
+  function daysIntoWeek() {
+    return ((daysAgo(0).getDay() - WEEK_START + 7) % 7) + 1;
+  }
+  function doneThisWeek(habit) {
+    var count = 0;
+    for (var i = 0; i < daysIntoWeek(); i++) {
+      if (habit.done[dateKey(daysAgo(i))]) count++;
+    }
+    return count;
+  }
   function toggleDay(habit, key) {
     if (habit.done[key]) delete habit.done[key];
     else habit.done[key] = true;
@@ -253,6 +304,7 @@
       });
 
     listEl.innerHTML = "";
+    renderWeekSummary();
 
     if (habits.length === 0) {
       var empty = document.createElement("div");
@@ -358,6 +410,53 @@
     });
   }
 
+  function renderWeekSummary() {
+    var box = document.getElementById("weekSummary");
+    box.innerHTML = "";
+    if (habits.length === 0) { box.hidden = true; return; }
+    box.hidden = false;
+
+    var soFar = daysIntoWeek();
+    var heading = document.createElement("h2");
+    heading.textContent = "This week";
+    var range = document.createElement("p");
+    range.className = "week-range";
+    range.textContent = prettyDate(daysAgo(soFar - 1)) + " – " + prettyDate(daysAgo(soFar - 7)) +
+      " · day " + soFar + " of 7";
+    box.appendChild(heading);
+    box.appendChild(range);
+
+    habits.forEach(function (habit) {
+      var count = doneThisWeek(habit);
+      var row = document.createElement("div");
+      row.className = "week-row";
+
+      var name = document.createElement("div");
+      name.className = "week-name";
+      name.textContent = habit.name;
+
+      var bar = document.createElement("div");
+      bar.className = "week-bar";
+      var fill = document.createElement("div");
+      fill.className = "week-bar-fill";
+      fill.style.width = (count / 7 * 100) + "%";
+      bar.appendChild(fill);
+
+      var countEl = document.createElement("div");
+      countEl.className = "week-count";
+      var strong = document.createElement("strong");
+      strong.textContent = count;
+      countEl.appendChild(strong);
+      countEl.appendChild(document.createTextNode(" of 7 days"));
+
+      row.title = habit.name + ": done " + count + (count === 1 ? " day" : " days") + " this week";
+      row.appendChild(name);
+      row.appendChild(bar);
+      row.appendChild(countEl);
+      box.appendChild(row);
+    });
+  }
+
   // ---------- Adding habits ----------
   document.getElementById("addForm").addEventListener("submit", function (e) {
     e.preventDefault();