Estimate NAT Gateway hourly and per-GB charges, the saving from gateway VPC endpoints, and the 55,000-connection limit.
A NAT Gateway carries two charges that are billed independently: an hourly charge for every gateway that exists, and a data processing charge for every GB that passes through in either direction. Because ingress and egress both count, a chatty workload can spend more on data processing than on the gateway itself, and traffic to S3 or DynamoDB can bypass the charge entirely through a free gateway VPC endpoint. NAT Gateway data processing is one of the most common surprises on an AWS bill, and the fix — a gateway endpoint or a per-zone gateway to avoid cross-zone transfer — is usually a one-day change.
NAT Gateway Cost
cost = gateways × hours × hourly rate + GB processed × per-GB rate.
cost = gateways × hours × hourly rate + GB processed × per-GB rate. A NAT Gateway carries two charges that are billed independently: an hourly charge for every gateway that exists, and a data processing charge for every GB that passes through in either direction. Because ingress and egress both count, a chatty workload can spend more on data processing than on the gateway itself, and traffic to S3 or DynamoDB can bypass the charge entirely through a free gateway VPC endpoint.
NAT Gateway data processing is one of the most common surprises on an AWS bill, and the fix — a gateway endpoint or a per-zone gateway to avoid cross-zone transfer — is usually a one-day change.
This calculator takes 7 inputs: NAT Gateways deployed, Price per NAT Gateway hour, Price per GB processed, Data processed per month, Of that, GB reachable via a gateway VPC endpoint, Peak connections to one destination, Billable hours per month. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.
The defaults are us-east-1 list prices used as a starting point, and NAT Gateway rates differ by region. Confirm the current price for your region on the Amazon VPC pricing page and overwrite the rate fields before you rely on the figure.
A NAT Gateway is a zonal resource. If instances in zone B route through a gateway in zone A, every byte also attracts cross-zone data transfer charges and the zone A outage takes zone B offline with it. One gateway per zone costs more in hourly charges but removes both problems.