diff --git a/mem/mem_windows.go b/mem/mem_windows.go
index 8c7fb1a13..e12fe54d7 100644
--- a/mem/mem_windows.go
+++ b/mem/mem_windows.go
@@ -48,7 +48,7 @@ func VirtualMemoryWithContext(ctx context.Context) (*VirtualMemoryStat, error) {
 		Total:       memInfo.ullTotalPhys,
 		Available:   memInfo.ullAvailPhys,
 		Free:        memInfo.ullAvailPhys,
-		UsedPercent: float64(memInfo.dwMemoryLoad),
+		UsedPercent: float64(memInfo.ullTotalPhys-memInfo.ullAvailPhys) / float64(memInfo.ullTotalPhys) * 100,
 	}
 
 	ret.Used = ret.Total - ret.Available