Bandwidth Cost Calculator

The bill for data leaving

Transferring 1,000 GB out of AWS with a 100 GB free allowance leaves 900 GB billable, costing about $81.00 at roughly $0.09 per GB — around ₹6,966 at ₹86 to the dollar.

Egress — data moving out of the cloud to the internet — is the charge that most often turns a predictable infrastructure bill into an unpredictable one. Inbound data is free on every major provider. Outbound is not, and it scales directly with how successful your application is.

How it is calculated

Billable data = total transferred − free allowance Cost = billable data × rate per GB

900 × $0.09 = $81.00.

Rates are tiered, falling as volume rises — AWS charges roughly $0.09/GB for the first 10 TB a month and less beyond, with similar structures at Azure and GCP. All three now include a free monthly allowance of around 100 GB.

What actually counts as egress

This is where estimates go wrong, because far more traffic is billable than people expect:

Internet egress — the obvious case, and the most expensive.

Cross-region transfer — moving data between regions is charged, typically $0.02/GB and upward. A multi-region architecture built for resilience generates this continuously.

Cross-availability-zone transfer — within a single region, traffic between AZs is charged on AWS at about $0.01/GB in each direction. A three-AZ Kubernetes cluster with pods chatting across zones can generate a surprising bill from internal traffic alone, and this is one of the most common unexplained line items in a container platform.

NAT Gateway processing — charged per GB processed in addition to the egress itself, so private-subnet instances reaching the internet pay twice.

Inbound is free everywhere. Traffic to the same AZ over private IPs is generally free.

Reducing it

Put a CDN in front. CloudFront, Azure CDN and Cloud CDN charge less per GB than raw egress and serve cached content without touching origin. For static assets this is usually the single largest saving available.

Compress. Gzip or Brotli on text, JSON and API responses commonly cuts transferred bytes by 60–80%. It is a configuration change, not an architecture change.

Keep chatty services in one AZ. Cross-AZ charges are avoidable by topology-aware routing, at some cost to resilience — a trade worth making deliberately rather than by accident.

Use VPC endpoints for traffic to provider services, avoiding NAT Gateway processing charges.

Check the Cloudflare route. Providers participating in the Bandwidth Alliance offer discounted or waived egress to certain partners, which for high-volume content delivery can be decisive.

Reading your estimate

The result covers internet egress at a single-tier rate. Real bills blend tiers, regions and transfer types, so treat this as a floor.

The free allowance differs by provider and has changed — all three major providers expanded free egress in recent years, partly in response to regulatory pressure on cloud switching costs. Both AWS and Google now waive egress charges entirely for customers leaving the platform, subject to conditions.

GST at 18% applies for Indian customers.

Common mistakes

Forgetting cross-AZ traffic. It is internal, it feels free, and it is not.

Serving media directly from object storage. A CDN is almost always cheaper at volume.

Ignoring logging and monitoring egress. Shipping verbose logs to an external service is egress like any other.

Assuming replication is free. Cross-region bucket replication generates continuous inter-region transfer.

Budgeting egress on average traffic. A single viral day or a misbehaving client retrying in a loop can exceed a month's expected transfer.