Azure NAT Gateway cost: hourly fee plus per-GB, like AWS

Quick answer

Azure NAT Gateway bills about $0.045 per hour plus about $0.045 per GB processed, the same shape as the AWS NAT gateway. For outbound-only internet access it is far cheaper than Azure Firewall (about $1.25/hour), so use NAT Gateway with NSGs unless you need firewall-grade inspection.

Azure NAT Gateway provides scalable outbound connectivity for a subnet without assigning public IPs to each resource. Its pricing mirrors the AWS NAT gateway: a modest hourly fee plus a per-gigabyte data-processing charge.

Two lines, both modest

Dimension	Rate (approximate)
NAT Gateway hours	~$0.045 / hour
Data processed	~$0.045 / GB

The hourly fee is small compared to Azure Firewall, and data processing at four and a half cents per gigabyte is the main variable at high volume. For typical outbound traffic the total is a fraction of a firewall.

NAT Gateway vs Azure Firewall

If you only need outbound internet access with source NAT, NAT Gateway plus network security groups does the job for a fraction of the Azure Firewall deployment fee. Choose the firewall only when you need application rules, centralized policy, threat intelligence, or inspection. For most outbound-only subnets, NAT Gateway is the cost-effective default.

Controlling the per-GB line

Data processing scales with outbound volume, so the same levers as elsewhere apply: keep traffic to Azure services on the Azure backbone with service endpoints or private endpoints so it does not traverse the NAT gateway, and reduce chatty outbound calls. See Azure egress bandwidth cost for the full outbound picture.

FAQ

How much does Azure NAT Gateway cost?

About $0.045 per hour plus about $0.045 per GB processed, the same shape as the AWS NAT gateway. For typical outbound traffic the total is modest and far below Azure Firewall.

Is Azure NAT Gateway cheaper than Azure Firewall?

For outbound-only internet access, yes, by a wide margin. NAT Gateway is about $0.045 per hour versus roughly $1.25 for Azure Firewall. Use NAT Gateway with NSGs unless you need firewall features like application rules or inspection.

When do I need Azure Firewall instead of NAT Gateway?

When you need centralized policy, application (FQDN) rules, threat intelligence, or traffic inspection. NAT Gateway only provides outbound source NAT, so pair it with NSGs for filtering; the firewall adds the advanced controls at a much higher fee.

How do I reduce Azure NAT Gateway data cost?

Keep traffic to Azure services on the backbone using service or private endpoints so it does not traverse the NAT gateway, and reduce chatty outbound calls. Data processing at about $0.045 per GB is the main variable at high volume.

Does Azure NAT Gateway charge for idle time?

Yes, the hourly fee runs continuously once deployed, but at about $0.045 per hour it is small. The larger variable is data processed, which scales with outbound traffic volume.

Does C3X estimate Azure NAT Gateway cost?

C3X prices the azurerm_nat_gateway resource from your Terraform, including the hourly fee, so the fixed cost appears before deploy. Data processing depends on traffic, which you provide as a usage assumption.

What to do next

Compare outbound options before you build. C3X reads your Terraform and prices NAT Gateway and the rest of your stack against a live catalog. Start with the quickstart.