Cloud Egress Cost Calculator
The cost of data leaving a cloud provider from the gigabytes transferred, the per-GB price after the free allowance, and what a CDN or a cheaper region would save.
Cloud providers charge for data leaving their network (egress) but not for data coming in.
How the cloud egress cost calculator works
Cloud providers charge for data leaving their network (egress) but not for data coming in. Prices are tiered, typically 0.05–0.12 per GB after a small free monthly allowance, and a CDN in front of the origin often serves the same bytes for less. Multiply the monthly gigabytes beyond the free tier by the price, and compare with the alternative price to see the saving.
Formula: cost = max(0, GB − free) × price per GB
Worked examples
| Inputs | Egress cost per month | Note |
|---|---|---|
| 5 TB a month, 100 GB free, 0.09 per GB | 441 | 441 a month; 196 via a CDN |
| A small site under the free tier | 0 | nothing |
| 100 TB a month at a 0.05 blended rate | 4,995 | 4,995 a month |
FAQFrequently asked questions
Why is egress charged and ingress not?
Providers want data to come in and stay; charging for leaving both recovers their transit costs and raises the cost of moving to a competitor. It is a common complaint, and some providers now waive it for customers who migrate away.
What counts as egress?
Bytes leaving the provider’s network to the internet, and often between regions or availability zones as well. Traffic within a zone, and to the provider’s own CDN, is usually free or cheaper.
How does a CDN save money?
The CDN fetches each object from the origin once and serves it many times from its own edge at a lower per-GB rate; the origin only pays egress for the cache fills. For static assets that is most of the traffic.
Are the tiers linear?
No — prices fall in steps at 10 TB, 50 TB and 150 TB a month. Enter the blended price for your volume, or the first-tier price for a conservative estimate.
Where these figures come from
- IEC 80000-13 — Information science and technology (quantities and units) — the decimal (kB, MB) versus binary (KiB, MiB) prefixes used throughout
- RFC 4632 — Classless Inter-domain Routing (CIDR) — the address-plan arithmetic behind the subnet calculator
- RFC 1918 — Address Allocation for Private Internets — the private ranges the subnet calculator recognises
- NIST SP 800-63B — Digital Identity Guidelines, Authentication — length over composition rules; the basis of the password guidance here
- NIST SP 800-57 Part 1 — Recommendation for Key Management — key-strength comparisons used by the key-space calculator
- National Cyber Security Centre — password guidance — UK national guidance on password policy
Last checked: September 2026. Units follow the SI decimal convention (IEC 80000-13 defines the binary alternatives); network and security figures cite the defining standard.