diff --git a/lib/linear_percent_indicator.dart b/lib/linear_percent_indicator.dart
index 6790aa5..255550a 100644
--- a/lib/linear_percent_indicator.dart
+++ b/lib/linear_percent_indicator.dart
@@ -7,6 +7,16 @@ extension ExtDouble on double {
   bool get isZero => this.toString() == '0.0';
 }
 
+extension ExtGlobalKey on GlobalKey {
+  Size getSize() {
+    final RenderObject? renderObject = currentContext?.findRenderObject();
+    if (renderObject is RenderBox && renderObject.hasSize) {
+      return renderObject.size;
+    }
+    return Size.zero;
+  }
+}
+
 // ignore: must_be_immutable
 class LinearPercentIndicator extends StatefulWidget {
   ///Percent value between 0.0 and 1.0
@@ -177,13 +187,14 @@ class _LinearPercentIndicatorState extends State<LinearPercentIndicator>
   void initState() {
     WidgetsBinding.instance.addPostFrameCallback((_) {
       if (mounted) {
+        final Size containerSize = _containerKey.getSize();
+        final Size indicatorSize = _keyIndicator.getSize();
         setState(() {
-          _containerWidth = _containerKey.currentContext?.size?.width ?? 0.0;
-          _containerHeight = _containerKey.currentContext?.size?.height ?? 0.0;
+          _containerWidth = containerSize.width;
+          _containerHeight = containerSize.height;
           if (_keyIndicator.currentContext != null) {
-            _indicatorWidth = _keyIndicator.currentContext?.size?.width ?? 0.0;
-            _indicatorHeight =
-                _keyIndicator.currentContext?.size?.height ?? 0.0;
+            _indicatorWidth = indicatorSize.width;
+            _indicatorHeight = indicatorSize.height;
           }
         });
       }