Lambda python code to get the total storage size of s3

Lambda code for that function :-

import boto3

def lambda_handler(event, context): # Create an S3 client s3_client = boto3.client('s3')

# Get a list of all buckets in the account
response = s3_client.list_buckets()

# Initialize a variable to track the total storage size
total_storage_size = 0

# Iterate through each bucket
for bucket in response['Buckets']:
    # Get the bucket name
    bucket_name = bucket['Name']

    # Get the size of the bucket
    bucket_size = get_bucket_size_recursive(s3_client, bucket_name)

    # Add the bucket size to the total storage size
    total_storage_size += bucket_size

# Print or log the total storage size
print(f"Total storage size for all buckets: {total_storage_size} GB")

# Return a response
return {
    'statusCode': 200,
    'body': f"Total storage size for all buckets: {total_storage_size} GB"
}

def get_bucket_size_recursive(s3_client, bucket_name): # Get the size of the bucket recursively bucket_size = 0

# Paginate through the objects in the bucket
paginator = s3_client.get_paginator('list_objects_v2')
pages = paginator.paginate(Bucket=bucket_name)

for page in pages:
    # Sum the size of objects in the bucket
    bucket_size += sum([obj['Size'] for obj in page.get('Contents', [])])

# Paginate through the subfolders (common prefixes)
pages = paginator.paginate(Bucket=bucket_name, Delimiter='/')

for page in pages:
   
    for common_prefix in page.get('CommonPrefixes', []):
        subfolder_size = get_bucket_size_recursive(s3_client, bucket_name + '/' + common_prefix['Prefix'])
        bucket_size += subfolder_size

return bucket_size / (1024 ** 3)  # Convert to GB

This is the code im used for to get the storage size of the s3. but i didn't get the exact storage match for this.

Test Event Name TestEvent

Response { "statusCode": 200, "body": "Total storage size: 128.38 GB" }

but in the storage its 280.80 GB. its not getting exact match, help me with this