Compare AWS S3, Cloudflare R2, Backblaze B2 and Supabase Storage with your actual usage.
| Feature | S3 | R2 | B2 | Supabase |
|---|---|---|---|---|
| Egress fees | $0.09/GB | Free | Free (w/ CF) | Varies |
| S3 compatibility | ✅ | ✅ | ✅ | Partial |
| CDN integration | CloudFront (paid) | Built-in CF | CF (free tier) | ❌ |
| Free tier | 5GB/12mo | 10GB/mo | 10GB/mo | 1GB |
| Best for | AWS ecosystem | High-egress | Budget backups | Postgres apps |
This calculator estimates the monthly bill for object storage across AWS S3, Cloudflare R2, Backblaze B2, and Supabase Storage using three inputs: stored data (GB), egress/download volume (GB), and API operations (per thousand). It matters because storage capacity is rarely the dominant cost — egress and per-request charges usually are. S3 bills roughly $0.023/GB-month for Standard storage but adds about $0.09/GB for internet data transfer out, while R2 charges for storage and operations with no egress fee, and B2 waives egress up to three times your stored volume. Entering your real numbers shows which provider is cheapest at your specific storage-to-transfer ratio instead of at a headline per-GB rate.
Storage is billed once per GB per month, but egress is billed on every byte a user or service downloads, so a busy 100 GB bucket can transfer many terabytes monthly. At roughly $0.09/GB, 1 TB of S3 downloads costs about $90 versus about $2.30 to store 100 GB — which is why zero-egress providers like R2 often win for read-heavy workloads.
They matter for workloads with many small objects or frequent listings. S3 charges per 1,000 requests, with writes (PUT, COPY, POST, LIST) priced roughly ten times higher than reads (GET); R2 and B2 use a similar Class A/Class B split. A million small uploads can cost more than the storage they produce, so the calculator separates operations from GB.
No. Price is one factor alongside compatibility, latency, and integration. S3 has the broadest ecosystem and direct integration with other AWS services (where transfer within the same region is often free), R2 is S3-API compatible and pairs with Cloudflare's CDN, B2 is lowest on raw storage price, and Supabase Storage bundles auth and database features. Also verify current published rates before committing, since pricing changes.