diff --git a/app/routes/checkin.py b/app/routes/checkin.py
index 0928f6a..73a6115 100644
--- a/app/routes/checkin.py
+++ b/app/routes/checkin.py
@@ -99,6 +99,72 @@ def create():
     return redirect(url_for("checkin.index"))
 
 
+@bp.route("/checkin/<int:checkin_id>/edit", methods=["GET"])
+@login_required
+def edit_form(checkin_id):
+    user = get_current_user()
+    checkin = query_one(
+        "SELECT * FROM checkins WHERE id = %s AND user_id = %s",
+        (checkin_id, user["id"]),
+    )
+    if not checkin:
+        return "", 404
+    return render_template("partials/checkin_edit_row.html", c=checkin, user=user)
+
+
+@bp.route("/checkin/<int:checkin_id>/view", methods=["GET"])
+@login_required
+def view_row(checkin_id):
+    user = get_current_user()
+    checkin = query_one(
+        "SELECT * FROM checkins WHERE id = %s AND user_id = %s",
+        (checkin_id, user["id"]),
+    )
+    if not checkin:
+        return "", 404
+    return render_template("partials/checkin_row.html", c=checkin, user=user)
+
+
+@bp.route("/checkin/<int:checkin_id>", methods=["PUT"])
+@login_required
+def update(checkin_id):
+    user = get_current_user()
+    weight_kg = request.form.get("weight_kg")
+    notes = request.form.get("notes", "").strip()
+
+    checkin = query_one(
+        "SELECT * FROM checkins WHERE id = %s AND user_id = %s",
+        (checkin_id, user["id"]),
+    )
+    if not checkin:
+        return "", 404
+
+    if not weight_kg:
+        flash("Weight is required.", "error")
+        return render_template("partials/checkin_edit_row.html", c=checkin, user=user)
+
+    try:
+        weight_kg = float(weight_kg)
+    except ValueError:
+        flash("Invalid weight value.", "error")
+        return render_template("partials/checkin_edit_row.html", c=checkin, user=user)
+
+    bmi = calculate_bmi(weight_kg, user.get("height_cm"))
+
+    execute(
+        """UPDATE checkins SET weight_kg = %s, bmi = %s, notes = %s
+           WHERE id = %s AND user_id = %s""",
+        (weight_kg, bmi, notes or None, checkin_id, user["id"]),
+    )
+
+    check_milestones(user["id"], user)
+
+    updated = query_one(
+        "SELECT * FROM checkins WHERE id = %s", (checkin_id,)
+    )
+    return render_template("partials/checkin_row.html", c=updated, user=user)
+
+
 @bp.route("/checkin/<int:checkin_id>", methods=["DELETE"])
 @login_required
 def delete(checkin_id):
diff --git a/app/templates/partials/checkin_edit_row.html b/app/templates/partials/checkin_edit_row.html
new file mode 100644
index 0000000..5e7763b
--- /dev/null
+++ b/app/templates/partials/checkin_edit_row.html
@@ -0,0 +1,19 @@
+<tr id="checkin-{{ c.id }}" class="editing-row">
+    <td>{{ c.checked_in_at | sydney }}</td>
+    <td>
+        <input type="number" name="weight_kg" class="edit-input" step="0.1" value="{{ '%.1f' % (c.weight_kg | float) }}"
+            required autofocus>
+    </td>
+    <td style="color: var(--text-muted); font-size: 0.8rem;">auto</td>
+    <td>
+        <input type="text" name="notes" class="edit-input" placeholder="Notes" value="{{ c.notes or '' }}">
+    </td>
+    <td>
+        <div class="checkin-actions">
+            <button class="btn-icon btn-icon-success" hx-put="/checkin/{{ c.id }}" hx-target="#checkin-{{ c.id }}"
+                hx-swap="outerHTML" hx-include="closest tr" title="Save">✓</button>
+            <button class="btn-icon" hx-get="/checkin/{{ c.id }}/view" hx-target="#checkin-{{ c.id }}"
+                hx-swap="outerHTML" title="Cancel">✕</button>
+        </div>
+    </td>
+</tr>
\ No newline at end of file
diff --git a/app/templates/partials/checkin_row.html b/app/templates/partials/checkin_row.html
index de60576..bebbd4c 100644
--- a/app/templates/partials/checkin_row.html
+++ b/app/templates/partials/checkin_row.html
@@ -4,7 +4,11 @@
     <td>{{ '%.1f' % (c.bmi | float) if c.bmi else '—' }}</td>
     <td>{{ c.notes or '—' }}</td>
     <td>
-        <button class="btn-icon" hx-delete="/checkin/{{ c.id }}" hx-target="#checkin-{{ c.id }}" hx-swap="outerHTML"
-            hx-confirm="Delete this check-in?">🗑️</button>
+        <div class="checkin-actions">
+            <button class="btn-icon" hx-get="/checkin/{{ c.id }}/edit" hx-target="#checkin-{{ c.id }}"
+                hx-swap="outerHTML" title="Edit">✏️</button>
+            <button class="btn-icon" hx-delete="/checkin/{{ c.id }}" hx-target="#checkin-{{ c.id }}" hx-swap="outerHTML"
+                hx-confirm="Delete this check-in?" title="Delete">🗑️</button>
+        </div>
     </td>
 </tr>
\ No newline at end of file