How to Choose the Right AWS Region

Choosing the wrong AWS region is an expensive mistake — not because of migration costs (though those are real), but because the price difference between regions can be 30–55% for identical workloads. This guide walks through the decision in order of importance.

Step 1: Start with compliance requirements

Start with the actual contractual, regulatory and service requirements. GDPR permits international transfers under specified safeguards; it is not a blanket EU-only hosting rule. FedRAMP scope depends on the authorized service and region, including eligible commercial US regions as well as GovCloud. A region tag in this tool does not establish compliance for your workload.

• EU-only residency: London (eu-west-2) is in the UK, outside the EU. Check your exact residency boundary.
• Canadian data residency: ca-central-1
• Australian data residency: ap-southeast-2
• US federal workloads: us-gov-east-1 or us-gov-west-1 (requires AWS GovCloud account)

Step 2: Filter by service availability

Not all AWS services are available in all regions. Service launches and instance availability differ by region. If you depend on a specific service — say, AWS Trainium for ML training, or AWS Local Zones for ultra-low latency — verify it's available in your candidate regions using the AWS Regional Services List.

Step 3: Evaluate latency from your users

Measure round-trip latency from where your users are, not from where your team is located. Tools like cloudping.info and the AWS Speed Test let you test latency to each region from your browser. A 50ms difference is imperceptible for most web applications; a 200ms difference is not.

• US East users: us-east-1 or us-east-2 (~8–15ms)
• US West users: us-west-2 (~12ms) or us-west-1 (more expensive)
• Western Europe users: eu-west-1 (Dublin), eu-west-2 (London), or eu-central-1 (Frankfurt)
• Asia-Pacific users: choose by sub-region — ap-northeast-1 (Tokyo), ap-southeast-1 (Singapore), ap-south-1 (Mumbai)

Step 4: Compare price

Shortlist regions that meet your service, resilience, data-location and latency requirements. Compare dated prices for the named SKU, then price your traffic, storage and eligible discounts. The on-demand ordering can change under negotiated or commitment pricing.

• AWS us-east-1 (m5.large): $0.0960/hr
• AWS us-east-2 (m5.large): $0.0960/hr
• AWS us-west-2 (m5.large): $0.0960/hr

Step 5: Consider carbon intensity

The lowest recorded AWS grid-intensity estimates in this dataset are below, observed 2026-10-08. They are a placement signal, not measurements of your application or a data centre. Compare price and benchmark shortlisted locations separately.

• eu-north-1: 8 gCO2eq/kWh
• sa-east-1: 64 gCO2eq/kWh
• eu-west-3: 74 gCO2eq/kWh