Mathieu KerbelFinOps
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What the traffic between two clouds will cost.

Splitting a system across two clouds adds lines nobody budgets: data leaving one to reach the other, NAT on the way out, traffic between zones, and the ports of a dedicated link. Price them before you move.

List prices, Paris regions · 1 USD = €0.89 · egress billed by tier · indicative, not a quote

01The setup

AWS and Google Cloud
Which two
Connection between them

02The transfer bill

Over the internet
  • Data out of AWSTo the internet, at the list rate€3,144
  • Data out of Google CloudTo the internet, at the list rate€1,012
  • NAT processingCharged per GB on the way out of private subnets, and per gateway hour€1,401
  • Traffic between zonesInside each cloud, charged per GB where the cloud charges it€684
  • Dedicated ports and cross-connectsNone on the internet path€0
  • Total a month€6,240

03Levers

Up to −€3,566 a month
Unit prices used Checked November 9, 2026
AWS, data out to the internet, 0 to 10 TB a month, per GB [1]$0.09
AWS, data out to the internet, 10 to 50 TB a month, per GB [1]$0.085
AWS, data out to the internet, 50 to 150 TB a month, per GB [1]$0.07
AWS, data out to the internet, above 150 TB a month, per GB [1]$0.05
AWS, data out through Direct Connect, per GB [1]$0.02
AWS, NAT gateway, per hour [2]$0.05
AWS, NAT processing, per GB [2]$0.05
AWS, between zones, per GB [2]$0.01 out + $0.01 in
AWS, Direct Connect 10 Gbps [1]$2.25 an hour
Google Cloud, data out to the internet, 0 to 1 TB a month, per GiB [6]$0.12
Google Cloud, data out to the internet, 1 to 10 TB a month, per GiB [6]$0.11
Google Cloud, data out to the internet, above 10 TB a month, per GiB [6]$0.08
Google Cloud, data out through Cloud Interconnect, per GiB [8]$0.02
Google Cloud, NAT gateway, per hour [7]$0.044
Google Cloud, NAT processing, per GiB [7]$0.045
Google Cloud, between zones, per GiB [6]$0.01
Google Cloud, Cloud Interconnect 10 Gbps [8]$2.428 an hour (circuit and VLAN attachment)
Cross-connects in a shared colocation, per month (assumption)$600

List prices in USD for the Paris regions (AWS eu-west-3, Azure France Central, Google Cloud europe-west9), 730 hours a month. Interconnect assumes one 10 Gbps link on each side plus about $600 a month of cross-connects in a shared colocation. Lever shares are rules of thumb: compression takes about 40% off text and JSON, a third of chatty traffic can usually stay inside one cloud, zone-aware routing keeps about 60% of calls in their zone.

How this is calculated

  • Internet egress is billed tranche by tranche, as each provider bills it, counted from the first GB of the month: other internet traffic on the same account would reach the cheaper tiers sooner. AWS's 100 GB a month free across services is not deducted; Azure's first 100 GB are free, a tier of its own meter.
  • Inbound traffic is free on all three. NAT is charged per GB on the sending side, and each NAT gateway for 730 hours; Google Cloud NAT at its hourly cap, more than 32 VMs on the gateway.
  • AWS charges a GB between zones once out and once in, Google Cloud once, Azure not at all.
  • The dedicated link is AWS Direct Connect's 10G port, Azure ExpressRoute's 10 Gbps metered circuit with its ErGw3AZ gateway, Google Cloud's 10 Gbps Dedicated Interconnect with one VLAN attachment. Your colocation and carrier fees are the cross-connect assumption above.
  • 1 TB = 1,024 GB; GB and GiB are counted alike. Euros at 1 USD = €0.89, the calculator's rate.

Sources

  1. AWS Price List bulk API, EU (Paris) eu-west-3: AWSDataTransfer, AmazonEC2 (NAT gateway) and AWSDirectConnect offers, checked October 30, 2026
  2. Published article: AWS NAT Gateway and data transfer (same NAT and zone rows, eu-west-3), checked October 16, 2026
  3. Azure Retail Prices API, France Central: Bandwidth, NAT Gateway and ExpressRoute meters, checked October 30, 2026
  4. Microsoft Learn, What are Azure availability zones?: no charge for data transfer between zones of a region, checked November 9, 2026
  5. Microsoft Learn, About ExpressRoute virtual network gateways: ErGw3AZ carries 10,000 Mbps, checked November 9, 2026
  6. Google Cloud, network pricing, europe-west9 (Paris): internet data transfer (Premium Tier, to Europe) and between zones, checked October 30, 2026
  7. Google Cloud, Cloud NAT pricing, checked October 30, 2026
  8. Google Cloud, Cloud Interconnect pricing (Dedicated Interconnect, Europe), checked October 30, 2026
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