diff --git a/public/include/pages/api/getnavbardata.inc.php b/public/include/pages/api/getnavbardata.inc.php
index 345dba0d..04f673ef 100644
--- a/public/include/pages/api/getnavbardata.inc.php
+++ b/public/include/pages/api/getnavbardata.inc.php
@@ -46,6 +46,11 @@ if ($iTotalRoundShares > 0) {
 // Round progress
 $iEstShares = $statistics->getEstimatedShares($dDifficulty);
 $dEstPercent = round(100 / $iEstShares * $aRoundShares['valid'], 2);
+if ($iEstShares > 0 && $aRoundShares['valid'] > 0) {
+    $dEstPercent = round(100 / $iEstShares * $aRoundShares['valid'], 2);
+} else {
+    $dEstPercent = 0;
+}
 
 // Output JSON format
 $data = array(