Data egress charges are calculated in several ways, depending on the type of service and the cloud provider. However, the basic process is the same.
Each cloud provider has sensors around its services, which facilitates the metering of all data traffic.
Each customer’s volume of data egress is recorded by the sensors and aggregated across all regions by service.
In some cases, customers are allowed “free” data egress up to a specific data volume—for example, 100 GB. Beyond that level, the customer is charged.
Each customer is invoiced for its data egress charges at the end of the monthly billing cycle.
To get a sense of what this could mean in the real world, consider that the median size of all pages on the web was 2,315 kilobytes in June 2022, according to HTTP Archive’s Web Almanac. Suppose a cloud-hosted website comprises median-size pages and receives 10,000 monthly visitors, with each viewing two pages. That website would generate approximately 44.2 GB of cloud data egress every month:
10,000 x 2 = 20,000
20,000 x 2,315 KB = 46.3 billion KB
46.3 billion KB / 1 GB (1,048,576 KB) = 44.155 GB