Where it runs is part of the price

Why it works that way

There is no such thing as the price of an m7i.large. There is a price per region. Same instance type, Linux, on-demand, shared tenancy, all pulled from the Price List API on the same day:

• us-east-1 (N. Virginia) and us-west-2 (Oregon): $0.1008/hour
• ap-south-1 (Mumbai): $0.10605
• eu-west-1 (Ireland): $0.11235
• eu-central-1 (Frankfurt): $0.12075
• ap-southeast-1 (Singapore): $0.126
• ap-northeast-1 (Tokyo): $0.1302
• af-south-1 (Cape Town): $0.13335
• sa-east-1 (São Paulo): $0.16065

Run one for a month, 730 hours, and that is $73.58 in N. Virginia against $117.27 in São Paulo. Nothing about the machine changed. A region is a physical place with its own power, land, transit and tax, and AWS prices each one against its own costs rather than against a global list. That is why the ordering is not a tidy map: Mumbai undercuts Frankfurt, and Ireland undercuts Singapore.

The bill names the region in the usage type prefix. USE2-BoxUsage:m7i.large is that instance in Ohio. The prefix is a short code from a table AWS publishes: USE1 us-east-1, USE2 us-east-2, USW2 us-west-2, CAN1 ca-central-1, EUC1 eu-central-1, APN1 ap-northeast-1, SAE1 sa-east-1, and so on. Four things about that prefix cause trouble:

• No prefix means us-east-1. BoxUsage:m7i.large, TimedStorage-ByteHrs and DataTransfer-Out-Bytes are all N. Virginia. us-east-1 predates the convention, so its older usage types never got a prefix. Newer ones do (CloudWatch bills USE1-DataScanned-Bytes there), so both forms coexist and mean the same region.
• EU is eu-west-1, not EUW1. Every other European region got a proper code (EUC1 Frankfurt, EUW2 London, EUN1 Stockholm). Ireland kept the original.
• The digits in the code are not the digits in the region name. APS1 is ap-southeast-1 (Singapore), APS3 is ap-south-1 (Mumbai), APS5 is ap-south-2 (Hyderabad). Read them as opaque labels and look them up.
• A few services print the full region code instead. KMS bills ap-northeast-1-KMS-Requests, not APN1-.

Two prefixes in a row means a pair of regions. USE1-APN1-AWS-Out-Bytes is bytes leaving N. Virginia for Tokyo.

What it costs

All three meters move with the region, not just the hourly one.

Time. EBS gp3 provisioned storage, per GB-month: $0.08 in us-east-1, $0.096 in ap-northeast-1, $0.152 in sa-east-1. Nearly double for a volume nobody has touched.

Bytes. S3 Standard, first 50 TB per month: $0.023/GB-month in us-east-1, $0.0245 in eu-central-1, $0.025 in ap-northeast-1, $0.0274 in af-south-1, $0.0405 in sa-east-1. That is 76% over N. Virginia. Internet egress, first 10 TB per month: $0.09/GB in us-east-1, $0.114 in ap-northeast-1, $0.15 in sa-east-1, $0.154 in af-south-1.

Units. S3 PUT/COPY/POST/LIST per 1,000 requests: $0.005 in us-east-1, $0.0047 in ap-northeast-1, $0.0054 in eu-central-1, $0.006 in af-south-1, $0.007 in sa-east-1. GET per 1,000: $0.0004 in us-east-1, $0.00037 in ap-northeast-1, $0.00056 in sa-east-1.

Look at Tokyo twice. Storage there costs 8.7% more than N. Virginia and requests cost about 7% less. The ranking is per meter, not per region. The cheaper region for a storage-heavy workload can be the dearer one for a request-heavy workload on the same service.

Global services have no region at all. Route 53 charges $0.50 per hosted zone per month for the first 25 and $0.40 per million standard queries for the first billion, and those rates apply wherever you are. The Price List records the location as “Any”, and the usage types (HostedZone, DNS-Queries) carry no prefix because there is nothing to name. CloudFront does vary, but not by AWS region: its usage types are edge geographies. Data transfer out to the internet, first 10 TB per month, is $0.085/GB under US- and EU-, $0.114 under JP-, $0.12 under AP-. The CloudFront bill groups these under Global, and Cost Explorer files them in a region-less bucket.

Exchange between Viewer in Japan, CloudFront edge, S3 ap-northeast-1, step by step:

1. Viewer in Japan to CloudFront edge: GET over HTTPS. Billed on the Units meter, JP · $0.012 / 10,000.
2. S3 ap-northeast-1 to CloudFront edge: Cache miss: 1 GB origin fetch. Not billed. (reply)
3. CloudFront edge to Viewer in Japan: 1 GB delivered. Billed on the Bytes meter, JP · $0.114/GB. (reply)

So why does a bill show us-east-1 usage for an account with nothing in N. Virginia? Because the side-effects of global services land there. Turn on additional CloudFront metrics and CloudFront sends up to eight metrics to CloudWatch in the US East (N. Virginia) Region. A distribution serving only Japan produces USE1- CloudWatch line items. A custom domain on that distribution needs an ACM certificate requested in us-east-1, because CloudFront accepts certificates from nowhere else. Billing and IAM console actions are logged in us-east-1. Virginia shows up because Virginia is where the global control plane lives.

Availability is a cost, not just a constraint. m8i.large is offered in 24 regions, including us-east-1, eu-west-2 and sa-east-1. It is not offered in eu-north-1 (Stockholm), ap-northeast-3 (Osaka), il-central-1 (Tel Aviv) or me-central-1 (UAE). When the thing you need is missing from your region, the design that follows (reach across to a region that has it, or replicate the data there) turns an availability gap into a recurring bytes charge.

Traps

A us-east-1 estimate is not a quote for anywhere else. Every AWS pricing page has a region selector with a default, and the default is rarely the region you are reading for. Read a number, set the selector, read it again. The Price List API is the cheaper habit: pull the same product with regionCode set to each candidate and compare the two rates directly.

Cheap compute, paid back in transfer. The inter-region egress rate belongs to the source region, and it is not symmetric. Out of us-east-1 it is $0.02/GB to essentially every other commercial region. Out of ap-northeast-1 it is $0.09/GB. Out of sa-east-1 to us-east-1 it is $0.138/GB: 6.9× the same wire in the other direction.

Path through S3 bucket, Batch worker, hop by hop:

• S3 bucket (ap-northeast-1)
• Batch worker (us-east-1) is billed on the Time meter for as long as it exists.

1. S3 bucket to Batch worker: Read 1 TB. Billed on the Bytes meter, $0.09/GB.
2. Batch worker to S3 bucket: Write results back. Billed on the Bytes meter, $0.02/GB.

Moving an m7i.large from Tokyo to N. Virginia saves $21.46 a month. One 1 TB read back out of Tokyo costs $92.16. The data did not move, so the saving is a one-off and the transfer is per gigabyte and grows with traffic.

EU- means two different things. For EC2 and data transfer, EU- is eu-west-1 in Ireland. For CloudFront, EU- is European edge locations and has nothing to do with Ireland. Same three characters, two namespaces; only the service column separates them.

Local Zones and Wavelength Zones are priced separately from their parent region. A c5.2xlarge is $0.34/hour in us-west-2. In the Los Angeles Local Zone it is LAX1-BoxUsage:c5.2xlarge at $0.408, a 20% premium. Others go further: Hamburg HAM1- $0.524, Perth PER1- $0.599, Lima LIM1- $0.655. Wavelength Zones get a compound code naming the parent: EUW3WL1DSS1-BoxUsage:c5.2xlarge is the Dakar Wavelength Zone under eu-west-3, at $0.461. On the bill these look like a region prefix you have never seen, which is exactly what they are.

Two regions’ prices move independently. us-east-1 and us-west-2 happen to charge the same for an m7i.large today. That is a fact about the current rate card, not a rule, and it says nothing about S3 or egress in either place. A multiplier you measured once is not a multiplier you can reuse. Re-pull both.