diff --git a/vrs/utils/FilterCopy.cpp b/vrs/utils/FilterCopy.cpp
index 76167391..68456bc3 100644
--- a/vrs/utils/FilterCopy.cpp
+++ b/vrs/utils/FilterCopy.cpp
@@ -100,7 +100,7 @@ int filterCopy(
   if (copyResult == 0) {
     // Init tracker progress early, to be sure we track the background thread queue size
     filteredReader.preRollConfigAndState(); // make sure to copy most recent config & state records
-    throttledWriter.initTimeRange(startTimestamp, endTimestamp);
+    throttledWriter.initTimeRange(startTimestamp, endTimestamp, &filteredReader.reader);
     filteredReader.iterateAdvanced(&throttledWriter);
     for (auto& filter : filters) {
       filter->flush();
diff --git a/vrs/utils/ThrottleHelpers.cpp b/vrs/utils/ThrottleHelpers.cpp
index 6ca8aa4f..0770bb1e 100644
--- a/vrs/utils/ThrottleHelpers.cpp
+++ b/vrs/utils/ThrottleHelpers.cpp
@@ -19,6 +19,7 @@
 #include <iomanip>
 #include <iostream>
 
+#include <vrs/RecordFileReader.h>
 #include <vrs/helpers/Strings.h>
 #include <vrs/os/Time.h>
 
@@ -73,9 +74,24 @@ RecordFileWriter& ThrottledWriter::getWriter() {
   return writer_;
 }
 
-void ThrottledWriter::initTimeRange(double minTimestamp, double maxTimestamp) {
+void ThrottledWriter::initTimeRange(double minTimestamp, double maxTimestamp, RecordFileReader* r) {
   minTimestamp_ = minTimestamp;
   duration_ = maxTimestamp - minTimestamp;
+  reader_ = r;
+  if (reader_ != nullptr && minTimestamp < maxTimestamp) {
+    auto* minRecord = reader_->getRecordByTime(minTimestamp);
+    if (minRecord != nullptr) {
+      minIndex_ = reader_->getRecordIndex(minRecord);
+      auto* maxRecord = reader_->getRecordByTime(maxTimestamp);
+      uint32_t maxIndex =
+          (maxRecord != nullptr) ? reader_->getRecordIndex(maxRecord) : reader_->getRecordCount();
+      indexRange_ = maxIndex - minIndex_;
+    } else {
+      indexRange_ = 0;
+    }
+  } else {
+    indexRange_ = 0;
+  }
 }
 
 void ThrottledWriter::onRecordDecoded(double timestamp, double writeGraceWindow) {
@@ -102,9 +118,18 @@ void ThrottledWriter::onRecordDecoded(double timestamp, double writeGraceWindow)
   if (showProgress()) {
     double now = os::getTimestampSec();
     if (now >= nextUpdateTime_) {
-      double progress = duration_ > 0.0001 ? (timestamp - minTimestamp_) / duration_ : 1.;
-      // timestamp ranges only include data records, but config & state records might be beyond
-      percent_ = max<int32_t>(static_cast<int32_t>(progress * 100), 0);
+      // timestamp range only includes data records, and config & state records might be beyond
+      if (reader_ == nullptr || indexRange_ == 0) {
+        double progress = duration_ > 0.0001 ? (timestamp - minTimestamp_) / duration_ : 1.;
+        percent_ = static_cast<int32_t>(progress * 100);
+      } else {
+        auto* record = reader_->getRecordByTime(timestamp);
+        uint32_t index = std::max<uint32_t>(
+            record != nullptr ? reader_->getRecordIndex(record) : reader_->getRecordCount(),
+            minIndex_);
+        percent_ = (100 * (index - minIndex_)) / indexRange_;
+      }
+      percent_ = max<int32_t>(percent_, 0);
       percent_ = min<int32_t>(percent_, 100);
       printPercentAndQueueSize(writer_.getBackgroundThreadQueueByteSize(), false);
       nextUpdateTime_ = now + kRefreshDelaySec;
diff --git a/vrs/utils/ThrottleHelpers.h b/vrs/utils/ThrottleHelpers.h
index 28ba8fbd..6812c029 100644
--- a/vrs/utils/ThrottleHelpers.h
+++ b/vrs/utils/ThrottleHelpers.h
@@ -40,10 +40,11 @@ class ThrottledWriter {
   /// @return The RecordFileWriter used to write the output file.
   RecordFileWriter& getWriter();
 
-  /// Set the range of timestamps expected, to track progress on the time range.
+  /// Set the range of timestamps expected, to track operation progress.
   /// @param minTimestamp: earliest timestamp of the operation
   /// @param maxTimestamp: latest timestamp of the operation
-  void initTimeRange(double minTimestamp, double maxTimestamp);
+  /// @param reader: the source file reader, which might allow us to track progress more precisely
+  void initTimeRange(double minTimestamp, double maxTimestamp, RecordFileReader* reader = nullptr);
 
   /// Called when a record is read, which can allow you to slow down decoding by adding a mere sleep
   /// in the callback itself. This is the main use case of this callback, as data is queued for
@@ -81,6 +82,9 @@ class ThrottledWriter {
   int32_t percent_ = 0;
   double minTimestamp_ = 0;
   double duration_ = 0;
+  RecordFileReader* reader_ = nullptr;
+  uint32_t minIndex_ = 0;
+  uint32_t indexRange_ = 0;
 };
 
 /// Default handling of file creation & closing, offering customization opportunities
diff --git a/vrs/utils/Validation.cpp b/vrs/utils/Validation.cpp
index 2ccd749e..a8112383 100644
--- a/vrs/utils/Validation.cpp
+++ b/vrs/utils/Validation.cpp
@@ -316,7 +316,7 @@ string decodeValidation(FilteredFileReader& filteredReader, const CopyOptions& c
   filteredReader.preRollConfigAndState(); // make sure to copy most recent config & state records
 
   ThrottledWriter throttledWriter(copyOptions);
-  throttledWriter.initTimeRange(startTimestamp, endTimestamp);
+  throttledWriter.initTimeRange(startTimestamp, endTimestamp, &filteredReader.reader);
 
   size_t readRecordCount = 0;
   bool noError = true;
@@ -382,7 +382,7 @@ string checkRecords(
   filteredReader.preRollConfigAndState(); // make sure to copy most recent config & state records
 
   ThrottledWriter throttledWriter(copyOptions);
-  throttledWriter.initTimeRange(startTimestamp, endTimestamp);
+  throttledWriter.initTimeRange(startTimestamp, endTimestamp, &filteredReader.reader);
 
   size_t decodedCount = 0;
   bool noError = true;
@@ -755,7 +755,7 @@ bool compareVRSfiles(
   first.preRollConfigAndState(); // make sure to copy most recent config & state records
 
   ThrottledWriter throttledWriter(copyOptions);
-  throttledWriter.initTimeRange(startTimestamp, endTimestamp);
+  throttledWriter.initTimeRange(startTimestamp, endTimestamp, &first.reader);
 
   map<StreamId, StreamId> idMap;
   if (!buildIdMap(first, second, idMap)) {