AWS to Azure data transfer cost
AWS to Azure costs AWS internet egress ($0.09/GB first 10 TB). Azure ingress is free. Reverse direction: Azure Zone 1 egress is $0.087/GB first 10 TB. Both clouds break tiers at 10 TB / 50 TB / 150 TB; Azure runs $0.002 to $0.003/GB cheaper in the first two bands and identical beyond, so Azure-out is the marginally cheaper direction at every volume.
Both directions, per volume
| Volume | AWS to Azure | Azure to AWS | Cheaper direction |
|---|---|---|---|
| 1 TB | $83.16 | $80.39 | Azure to AWS (-3%) |
| 10 TB | $912.60 | $882.18 | Azure to AWS (-3%) |
| 50 TB | $4,394.70 | $4,282.26 | Azure to AWS (-3%) |
| 100 TB | $7,980.20 | $7,867.56 | Azure to AWS (-1%) |
| 1 PB | $56,315.00 | $56,202.36 | Azure to AWS (-0.2%) |
Numbers exclude NAT Gateway charges (AWS side) or ExpressRoute (Azure side). For per-byte API charges, both clouds free of API-call fees in the typical S3 / Blob transfer.
Where the asymmetry comes from
Azure and AWS share the same tier bands (first 10 TB, next 40 TB, next 100 TB, over 150 TB), but Azure prices the first two slightly lower: $0.087 versus $0.09, then $0.083 versus $0.085. Beyond 50 TB the rates converge at $0.07/GB and $0.05/GB, so the Azure-out advantage shrinks from about 3 percent at low volume to a rounding error at petabyte scale.
Operational note: Azure ingress from AWS often shows up in Azure Cost Management as "data in" with zero cost. The Azure side will not warn you about the AWS-side egress bill. You only see it on your AWS invoice. For multi-cloud workloads, build a script that joins both bills weekly so you do not get surprised.
See also: AWS to GCP transfer, Azure to GCP transfer, Multi-cloud replication math.