diff --git a/src/main/java/org/apache/commons/sanselan/formats/tiff/datareaders/DataReaderStrips.java b/src/main/java/org/apache/commons/sanselan/formats/tiff/datareaders/DataReaderStrips.java
index 51d1a1b..3c42537 100644
--- a/src/main/java/org/apache/commons/sanselan/formats/tiff/datareaders/DataReaderStrips.java
+++ b/src/main/java/org/apache/commons/sanselan/formats/tiff/datareaders/DataReaderStrips.java
@@ -95,8 +95,9 @@
             long rowsPerStripLong = 0xFFFFffffL & rowsPerStrip;
             long rowsRemaining = height - (strip * rowsPerStripLong);
             long rowsInThisStrip = Math.min(rowsRemaining, rowsPerStripLong);
+            long bytesPerRow = (bitsPerPixel * width + 7) / 8;
+            long bytesPerStrip = rowsInThisStrip * bytesPerRow;
             long pixelsPerStrip = rowsInThisStrip * width;
-            long bytesPerStrip = ((pixelsPerStrip * bitsPerPixel) + 7) / 8;
 
             byte compressed[] = imageData.strips[strip].data;
 
@@ -108,4 +109,4 @@
         }
     }
 
-}
\ No newline at end of file
+}