diff --git a/backend/src/lib/workforce.js b/backend/src/lib/workforce.js
index 01e204b..28a87c2 100644
--- a/backend/src/lib/workforce.js
+++ b/backend/src/lib/workforce.js
@@ -367,8 +367,9 @@ async function fetchTimesheetsByDay(from, to, locationDeptIds) {
           return locationDeptIds.has(String(sh.department_id ?? 'unknown'))
         })
         if (hasLocationShift) {
-          const tCost   = parseFloat(t.cost             ?? 0)
-          const tOncost = parseFloat(t.cost_with_oncosts ?? t.cost ?? 0)
+          // Timesheet-level cost field is `total_cost` (not `cost` or `cost_with_oncosts`)
+          const tCost   = parseFloat(t.total_cost ?? t.cost ?? 0)
+          const tOncost = parseFloat(t.cost_with_oncosts ?? t.total_cost ?? t.cost ?? 0)
           const isLeaveTs = t.leave_request_id != null
           if (isLeaveTs) { tsLeaveBaseCost += tCost; tsLeaveOncostTotal += tOncost }
           else           { tsBaseCost      += tCost; tsOncostTotal      += tOncost }