Data Egress Cost Calculator

billable = origin GB − free allowance; cost = Σ (GB falling in each band × that band's rate) + CDN GB × CDN rate + cross-zone GB × cross-zone rate. Egress is priced as a step ladder, not a single rate: only the gigabytes that fall inside a band are charged at that band's price, so the marginal rate falls as volume grows while the average lags behind it. CDN traffic leaves the ladder entirely and is billed at CDN rates, which is why offload changes the shape of the bill and not just its size.

Egress is the meter that scales with your users rather than your architecture, and it is the one most often missing from a cost model until the first busy month arrives. Rates and band boundaries vary by provider and region, so treat the defaults as a starting point and confirm them on your own invoice.

This calculator takes 10 inputs: Internet egress per month, Free tier allowance, Rate for the first 10 TB, Rate for the next 40 TB, Rate for the next 100 TB, Rate beyond 150 TB, Traffic served through a CDN, CDN egress rate, Cross-zone traffic inside the region, Cross-zone rate. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.

It never touches the internet, so it does not consume the free allowance or the tiered ladder, but most providers still charge roughly a cent per gigabyte in each direction. A chatty service spread across three zones can spend more on cross-zone transfer than on internet egress.