diff --git a/backend/app/api/routes/archives.py b/backend/app/api/routes/archives.py
index 5ed61ed85..47fe87a6b 100644
--- a/backend/app/api/routes/archives.py
+++ b/backend/app/api/routes/archives.py
@@ -570,7 +570,7 @@ async def get_archive_stats(
                     total_energy_kwh += mqtt_data.energy
 
         total_energy_kwh = round(total_energy_kwh, 3)
-        total_energy_cost = round(total_energy_kwh * energy_cost_per_kwh, 2)
+        total_energy_cost = round(total_energy_kwh * energy_cost_per_kwh, 3)
     else:
         # Print mode: sum up per-print energy from archives
         energy_kwh_result = await db.execute(select(func.sum(PrintArchive.energy_kwh)))
@@ -591,7 +591,7 @@ async def get_archive_stats(
         average_time_accuracy=average_accuracy,
         time_accuracy_by_printer=accuracy_by_printer if accuracy_by_printer else None,
         total_energy_kwh=round(total_energy_kwh, 3),
-        total_energy_cost=round(total_energy_cost, 2),
+        total_energy_cost=round(total_energy_cost, 3),
     )
 
 
diff --git a/backend/app/api/routes/projects.py b/backend/app/api/routes/projects.py
index 4e9eb588f..bf31f2d87 100644
--- a/backend/app/api/routes/projects.py
+++ b/backend/app/api/routes/projects.py
@@ -144,7 +144,7 @@ async def compute_project_stats(
         parts_progress_percent=parts_progress_percent,
         estimated_cost=round((sums.total_filament_cost or 0), 2),
         total_energy_kwh=round((sums.total_energy or 0), 3),
-        total_energy_cost=round((sums.total_energy_cost or 0), 2),
+        total_energy_cost=round((sums.total_energy_cost or 0), 3),
         remaining_prints=remaining_prints,
         remaining_parts=remaining_parts,
         bom_total_items=bom_stats.total or 0,
diff --git a/backend/app/main.py b/backend/app/main.py
index 05c24d367..d948f92c8 100644
--- a/backend/app/main.py
+++ b/backend/app/main.py
@@ -2447,7 +2447,7 @@ async def on_print_complete(printer_id: int, data: dict):
 
                         energy_cost_per_kwh = await get_setting(db, "energy_cost_per_kwh")
                         cost_per_kwh = float(energy_cost_per_kwh) if energy_cost_per_kwh else 0.15
-                        energy_cost = round(energy_used * cost_per_kwh, 2)
+                        energy_cost = round(energy_used * cost_per_kwh, 3)
 
                         from backend.app.models.archive import PrintArchive
 
diff --git a/frontend/src/components/SmartPlugCard.tsx b/frontend/src/components/SmartPlugCard.tsx
index 29c19f3f2..afe07c786 100644
--- a/frontend/src/components/SmartPlugCard.tsx
+++ b/frontend/src/components/SmartPlugCard.tsx
@@ -265,7 +265,7 @@ export function SmartPlugCard({ plug, onEdit }: SmartPlugCardProps) {
               )}
               {status.energy.today !== null && status.energy.today !== undefined && (
                 <div className="flex-1 text-center border-l border-bambu-dark-tertiary">
-                  <p className="text-lg font-semibold text-white">{status.energy.today.toFixed(2)}</p>
+                  <p className="text-lg font-semibold text-white">{status.energy.today.toFixed(3)}</p>
                   <p className="text-xs text-bambu-gray">kWh Today</p>
                 </div>
               )}
diff --git a/frontend/src/pages/ProjectDetailPage.tsx b/frontend/src/pages/ProjectDetailPage.tsx
index 38b3e2aba..f9e1f9b47 100644
--- a/frontend/src/pages/ProjectDetailPage.tsx
+++ b/frontend/src/pages/ProjectDetailPage.tsx
@@ -640,7 +640,7 @@ export function ProjectDetailPage() {
                 <div>
                   <p className="text-xs text-bambu-gray uppercase">{t('projectDetail.cost.energy')}</p>
                   <p className="text-lg font-semibold text-white">
-                    {stats.total_energy_kwh.toFixed(2)} kWh
+                    {stats.total_energy_kwh.toFixed(3)} kWh
                     {stats.total_energy_cost > 0 && (
                       <span className="text-sm text-bambu-gray ml-1">
                         ({currency}{stats.total_energy_cost.toFixed(2)})
diff --git a/frontend/src/pages/SettingsPage.tsx b/frontend/src/pages/SettingsPage.tsx
index b2532e189..13ef799ce 100644
--- a/frontend/src/pages/SettingsPage.tsx
+++ b/frontend/src/pages/SettingsPage.tsx
@@ -1527,7 +1527,7 @@ export function SettingsPage() {
                   </span>
                   <input
                     type="number"
-                    step="0.01"
+                    step="0.001"
                     min="0"
                     value={localSettings.energy_cost_per_kwh}
                     onChange={(e) =>
@@ -2580,7 +2580,7 @@ export function SettingsPage() {
                         Today
                       </div>
                       <div className="text-xl font-bold text-white">
-                        {plugEnergySummary.totalToday.toFixed(2)}
+                        {plugEnergySummary.totalToday.toFixed(3)}
                         <span className="text-sm font-normal text-bambu-gray ml-1">kWh</span>
                       </div>
                       {(localSettings?.energy_cost_per_kwh ?? 0) > 0 && (
@@ -2597,7 +2597,7 @@ export function SettingsPage() {
                         Yesterday
                       </div>
                       <div className="text-xl font-bold text-white">
-                        {plugEnergySummary.totalYesterday.toFixed(2)}
+                        {plugEnergySummary.totalYesterday.toFixed(3)}
                         <span className="text-sm font-normal text-bambu-gray ml-1">kWh</span>
                       </div>
                       {(localSettings?.energy_cost_per_kwh ?? 0) > 0 && (
diff --git a/frontend/src/pages/StatsPage.tsx b/frontend/src/pages/StatsPage.tsx
index 3d05b56fd..9a88c0fe8 100644
--- a/frontend/src/pages/StatsPage.tsx
+++ b/frontend/src/pages/StatsPage.tsx
@@ -91,7 +91,7 @@ function QuickStatsWidget({
         </div>
         <div>
           <p className="text-xs text-bambu-gray">{t('stats.energyUsed')}</p>
-          <p className="text-xl font-bold text-white">{stats?.total_energy_kwh.toFixed(2) || '0.00'} kWh</p>
+          <p className="text-xl font-bold text-white">{stats?.total_energy_kwh.toFixed(3) || '0.000'} kWh</p>
         </div>
       </div>
       <div className="flex items-start gap-3">