diff --git a/src/sampled_values/sv_publisher.c b/src/sampled_values/sv_publisher.c
index d5ee8d05..c759c56f 100644
--- a/src/sampled_values/sv_publisher.c
+++ b/src/sampled_values/sv_publisher.c
@@ -367,7 +367,15 @@ SVPublisher_ASDU_getEncodedSize(SVPublisher_ASDU self)
         encodedSize += 4;
 
     /* sample */
-    encodedSize += 2;
+    if (self->dataSize < 128)
+        encodedSize += 2;
+    else if (self->dataSize < 256)
+        encodedSize += 3;
+    else if (self->dataSize < 65535)
+        encodedSize += 4;
+    else
+        encodedSize += 5;
+
     encodedSize += self->dataSize;
 
     /* smpMod */