diff --git a/documentation/Sphinx/user_guide/output/post-processing.rst b/documentation/Sphinx/user_guide/output/post-processing.rst
index 948614ee..6a669f9d 100644
--- a/documentation/Sphinx/user_guide/output/post-processing.rst
+++ b/documentation/Sphinx/user_guide/output/post-processing.rst
@@ -50,6 +50,9 @@ script, these are given in the table below.
     * - ``-i/ --input_name``
       - vernier-output-
       - Vernier files to read from
+    * - ``-d/ --decimals``
+      - 3
+      - Number of decimal places to report calculated values to
     * - ``-m/ --max_only``
       - False
       - If used will only calculate maximum values across MPI ranks
@@ -59,6 +62,7 @@ script, these are given in the table below.
 
 Below is an example of the current script output without additional flags.
 
+
 .. code-block:: text
 
                            Routine  Mean_Total  Min_Total  Max_Total  Mean_Self   Min_Self   Max_Self
diff --git a/post-processing/post-process.py b/post-processing/post-process.py
index ce9db005..6baf32b7 100755
--- a/post-processing/post-process.py
+++ b/post-processing/post-process.py
@@ -29,11 +29,13 @@ def parse_cli_arguments(input_arguments: list[str] = None,
     """
 
     parser = argparse.ArgumentParser(description="This script is for merging the outputs from a test that uses Vernier callipers into one file. For full documentation please see the post-processing section of the user guide.")
+
     parser.add_argument("-p", "--path",         type=Path,  default=(os.getcwd()),                help="Path to Vernier output files")
     parser.add_argument("-o", "--output_name",  type=str,   default=str("vernier-merged-output"), help="Name of file to write to")
     parser.add_argument("-i", "--input_name",   type=str,   default=str("vernier-output-"),       help="Vernier files to read from")
     parser.add_argument("-m", "--max_only",     action="store_true", default=False,               help="Only calculates the maximum value across all ranks")
     parser.add_argument("-f", "--full_info",    action="store_true", default=False,               help="Enables merging and displaying of all information Vernier records")
+    parser.add_argument("-d", "--decimals",     type=int,   default=3,                            help="Number of decimal places calculated results will be reported to")
 
     return parser.parse_args(args=input_arguments)
 
@@ -193,8 +195,14 @@ def main():
     input_name = args.input_name
     max_only_bool = args.max_only
     full_info_bool = args.full_info
+    decimals = args.decimals
+
     mpiranks = read_mpi_ranks(file_path, input_name)
 
+    if decimals >= 4:
+
+        print("WARNING: Vernier typically reports values to 3 d.p, so calculated values may not be accurate or representative at higher precisions and may not display correctly")
+
     if mpiranks == 0:
 
         print("Error, no vernier-outputs detected")
@@ -209,7 +217,7 @@ def main():
 
         thread_string = "@0" 
         merged_frame["Routine"] = merged_frame["Routine"].str.replace(thread_string, '')
-
+        merged_frame = merged_frame.round(decimals)
         print("\nWriting...")
         with open(f"{merged_file_name}", 'w') as f:
                   f.write(merged_frame.to_string(index=False, col_space=10))