AWS NAT Gateway Cost Calculator

Estimate NAT Gateway-style cost using a simple model: hourly gateway fees + per-GB data processing. Use hours/day x days/month to normalize uptime and compare baseline vs peak traffic.

Maintained by CloudCostKit Editorial Team. Last updated: 2026-01-28. Editorial policy and methodology.

Best next steps

Use this calculator for the first estimate, then validate the answer with the closest guide or companion tool.

AWS network cost hub Guide: NAT gateway cost (why it spikes) Guide: estimate NAT GB processed Guide: NAT cost optimization

Inputs

NAT gateways
Hours/day
Days/month
Use 30.4 for an average month.
Monthly hours: 730
Price ($ / NAT gateway-hour)
Data processed (GB / month)
Avg throughput 6.09 Mbps.
Avg throughput (Mbps)
Use avg egress over the month.
Est 19,699 GB/month.
Price ($ / GB processed)
Scenario presets

Results

Estimated monthly total
$122.83
Hourly component
$32.83
Traffic component
$90.00
GB processed
2,000
Traffic share
73.3%

NAT cost has a fixed floor and a traffic multiplier

NAT Gateway bills usually become confusing because two different cost shapes are mixed together: a relatively predictable gateway-hour floor and a workload-driven GB processed multiplier. This page is most useful when you separate those two lines before thinking about optimization.

  • Fixed base: gateway count by AZ and runtime window.
  • Variable line: all traffic that traverses the gateway, including hidden fleet-wide downloads.
  • Review lens: hourly cost tells you footprint; processed GB tells you behavior.

What usually makes NAT bills spike

NAT rarely explodes because of one user request. The common pattern is fan-out: every node, task, or instance repeating the same pulls, updates, package downloads, or retries. That is why NAT can look quiet in architecture diagrams but expensive in the bill.

  • Image pulls and bootstrap traffic: cluster scale-outs multiply outbound traffic quickly.
  • Patch windows: package mirrors and OS updates create short but expensive bursts.
  • Retry storms: incidents can inflate processed GB without obvious product growth.
  • Shared egress paths: one NAT serving many workloads hides which team is actually driving cost.

When NAT is the bill to reduce, and when it is just the symptom

  • If processed GB dominates, investigate endpoints, mirrors, caching, and route-local traffic first.
  • If gateway-hours dominate, review whether you have too many always-on gateways for the actual topology.
  • If NAT drops but cross-AZ or endpoint charges rise elsewhere, you moved the path rather than removed the cost.
  • Always compare before-and-after architecture changes across the whole network bill, not only the NAT line.

Baseline vs patch-window NAT scenarios

Scenario Gateways GB processed Notes
Baseline Current Expected Normal releases
Peak Current High Patch/upgrade window

What to validate after routing changes

  • Watch NAT GB processed trend (it should drop if endpoints/caching are working).
  • Confirm you did not increase cross-AZ, cross-region, or endpoint spend elsewhere while reducing NAT.
  • Re-check during deploy, patch, and incident windows because that is where the hidden multipliers usually live.
  • Compare gateway-hours and processed GB against billing usage types before deciding the optimization really worked.

Next steps

AWS network cost hub NAT vs endpoints break-even VPC endpoints pricing

Example scenario

  • 1 NAT gateway running 24 hours/day for 30 days with 2,000 GB processed - estimate hourly + traffic charges.
  • Peak 220% scenario highlights bursty update or deploy traffic.

Included

  • Hourly component from NAT gateways x hours/day x days/month x $/hour.
  • Traffic component from GB processed x $/GB processed.
  • Optional Mbps to monthly GB estimator.
  • Baseline vs peak scenario table for traffic spikes.

Not included

  • Internet egress $/GB charges (model separately if applicable).
  • Other transfer fees (cross-AZ/cross-region) depending on your architecture.

How we calculate

  • Hourly cost = NAT gateways x (hours/day x days/month) x $ per NAT gateway-hour.
  • Traffic cost = GB processed per month x $ per GB processed.
  • Total = hourly cost + traffic cost.

FAQ

What is "GB processed" for NAT Gateway?
It's the volume of traffic that traverses the NAT gateway. Track it via VPC Flow Logs or NAT metrics, or estimate from throughput over time.
Does this include internet egress charges?
No. NAT Gateway has its own hourly and processing fees, but you may still have separate internet egress costs depending on the destination and service.
Why do NAT bills spike?
Costs scale with both time (gateway-hours) and traffic (GB processed). High-throughput workloads, software updates, or container image pulls behind NAT can quickly increase GB processed.

Related tools

AWS network cost hub Guide: NAT gateway cost (why it spikes) Guide: estimate NAT GB processed Guide: NAT cost optimization Guide: NAT vs VPC endpoints (cost) VPC interface endpoint cost VPC data transfer cost

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Disclaimer

Educational use only. Not legal, financial, or professional advice. Results are estimates based on the inputs and assumptions shown on this page. Verify pricing and limits with your providers and documentation.

Last updated: 2026-01-28. Reviewed against CloudCostKit methodology and current provider documentation. See the Editorial Policy .