AWS S3 Data Transfer Bandwidth and Cost

Estimate AWS S3 data transfer times and associated egress costs. Calculate bandwidth needs for S3 uploads, downloads, and cross-region replication.

Backup & Cloud

Detailed Explanation

S3 Data Transfer Bandwidth and Cost Estimation

AWS S3 transfers are governed by both bandwidth limits and cost considerations. Understanding both dimensions is essential for architecture decisions.

S3 Upload Performance

Single-stream upload throughput depends on object size and connection:

Upload Method Typical Throughput
Single PUT (< 5 GB) 25-100 Mbps
Multipart Upload 100-500 Mbps
S3 Transfer Acceleration 200-800 Mbps
AWS Direct Connect (1G) ~800 Mbps
AWS Direct Connect (10G) ~8 Gbps

Egress Cost Calculation

AWS charges for data leaving S3 (egress) but not for data entering (ingress):

Monthly Egress Cost per GB
First 10 TB $0.09
Next 40 TB $0.085
Next 100 TB $0.07
Over 150 TB $0.05

Example: Daily 100 GB Egress

Monthly egress: 100 GB * 30 = 3,000 GB = 3 TB
Cost: 3,000 * $0.09 = $270/month

Bandwidth needed for 100 GB in 8-hour window:
100 GB * 8 bits / (8 * 3600 seconds) = ~27.8 Mbps sustained

Cross-Region Replication

Replicating a 1 TB bucket to a secondary region:

Initial sync: 1 TB at ~200 Mbps = ~11 hours
Transfer cost: 1,000 GB * $0.02 = $20 (inter-region)

Ongoing replication adds latency of seconds to minutes depending on object size and region distance.

Optimizing Transfer Speed

  1. Multipart upload: Split files > 100 MB into parts uploaded in parallel
  2. Transfer Acceleration: Uses CloudFront edge locations for faster global uploads
  3. VPC Endpoints: Avoid public internet for EC2-to-S3 transfers (no cost, higher throughput)
  4. Compression: Compress before upload to reduce both time and storage costs

Use Case

Cloud architects estimating data transfer costs for S3-heavy workloads, DevOps engineers optimizing CI/CD artifact storage and retrieval, data engineers planning ETL pipeline bandwidth and cost budgets, and finance teams forecasting AWS data transfer line items.

Try It — Bandwidth Calculator

Open full tool