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.

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%

How to get your inputs

  • NAT gateways: count NAT gateways per AZ (teams often run 1 per AZ for HA).
  • Hours/day and days/month: use real uptime windows (24 x 30.4 for always-on).
  • GB processed: pull from NAT metrics or VPC Flow Logs, or estimate from throughput charts (Mbps to GB/month).
  • Pricing: use region-specific NAT hourly and per-GB rates.

Result interpretation

  • If traffic share is high, focus on data path changes (endpoints, caching, or egress routing).
  • If hourly share dominates, review gateway count and uptime windows.

Common mistakes

  • Modeling only the hourly fee and ignoring GB processed (usually the bigger driver).
  • Forgetting that "small" downloads multiply across fleets (node bootstrap, image pulls, package updates).
  • Ignoring retries/timeouts that multiply outbound traffic during incidents.
  • Assuming endpoints automatically replace NAT without checking the traffic mix.
  • Estimating GB from peak throughput without averaging over the month.

Scenario planning

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

Validate after changes

  • Watch NAT GB processed trend (it should drop if endpoints/caching are working).
  • Confirm you did not increase cross-AZ/cross-region transfer elsewhere.
  • Re-check during peak/incident windows (that's when hidden multipliers show up).
  • Compare NAT gateway-hours and GB processed with billing line items.

Next steps

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