diff --git a/internal/tui/tab_sites.go b/internal/tui/tab_sites.go
index a4efcf4..12787e7 100644
--- a/internal/tui/tab_sites.go
+++ b/internal/tui/tab_sites.go
@@ -360,8 +360,9 @@ func (m Model) computeLayout() tableLayout {
 		{"RT", "RETRIES", 5, 9},
 	}
 
-	overhead := 30
-	usable := m.termWidth - chromePadH - 2 - overhead
+	numCols := len(cols)
+	borderOverhead := 2 + (numCols - 1) // left + right border + column separators
+	usable := m.termWidth - chromePadH - 2 - borderOverhead
 	if usable < 80 {
 		usable = 80
 	}