diff --git a/app/routes/reports.py b/app/routes/reports.py
index f244f3c..294425b 100644
--- a/app/routes/reports.py
+++ b/app/routes/reports.py
@@ -1,14 +1,21 @@
 from flask import Blueprint, render_template, request
 from datetime import date
+from collections import defaultdict
 import sqlalchemy as sa
 from app import db
 from app.models import WorkEntry
 from app.business.travel_calc import compute_km_for_entry, compute_co2_grams, compute_frais_reels
-from app.business.time_calc import count_day_types
+from app.business.time_calc import count_day_types, monthly_stats, minutes_to_str
 from app.config_loader import get_vehicles, get_journeys, get_bareme
 
 bp = Blueprint("reports", __name__, url_prefix="/reports")
 
+MONTHS_FR = {
+    1: "Janvier", 2: "Février", 3: "Mars", 4: "Avril",
+    5: "Mai", 6: "Juin", 7: "Juillet", 8: "Août",
+    9: "Septembre", 10: "Octobre", 11: "Novembre", 12: "Décembre",
+}
+
 
 @bp.route("/")
 def index():
@@ -23,6 +30,7 @@ def index():
     vehicles = get_vehicles()
     journeys = get_journeys()
 
+    # --- Stats annuelles (inchangées) ---
     total_km = {}
     total_co2 = 0.0
     for entry in entries:
@@ -42,6 +50,32 @@ def index():
 
     day_type_counts = count_day_types(entries)
 
+    # --- Stats mensuelles ---
+    entries_by_month: dict[int, list] = defaultdict(list)
+    for entry in entries:
+        entries_by_month[entry.date.month].append(entry)
+
+    monthly_data = {}
+    for month in range(1, 13):
+        month_entries = entries_by_month.get(month, [])
+
+        month_km: dict[str, int] = {}
+        for entry in month_entries:
+            km = compute_km_for_entry(entry.journey_profile_id, journeys, entry.motor_vehicle_id)
+            for v, d in km.items():
+                month_km[v] = month_km.get(v, 0) + d
+
+        stats = monthly_stats(month_entries)
+
+        monthly_data[month] = {
+            "month_name": MONTHS_FR[month],
+            "entry_count": len(month_entries),
+            "km_by_vehicle": month_km,
+            "km_total": sum(month_km.values()),
+            "median_daily_str": minutes_to_str(stats["median_daily_min"]) if month_entries else "–",
+            "median_weekly_str": minutes_to_str(stats["median_weekly_min"]) if month_entries else "–",
+        }
+
     return render_template(
         "reports.html",
         year=year,
@@ -50,4 +84,5 @@ def index():
         frais_reels=frais_reels,
         vehicles=vehicles,
         day_type_counts=day_type_counts,
+        monthly_data=monthly_data,
     )