How to correctly estimate Azure Key Vault cost

Question

Hello, i have a doubt about how to estimate the cost of using an azure key vault in the following scenario:

the vault will hold 3 SSL certificates, each for a different web service, apart from that every xxx days before the ssl certificate expiration date it should use the key vault alert to call a azure batch(using azure event grid) to run a container that will generate and update said SSL certificate.(the update will be managed from the container logic not an autorenewal from inside the key vault)

in the calculator there only show operations estimates but there is no detail on how many times it access the vault when a user visit the site an use the SSL, or if it also includes the calls to the event grid from the azure key vault alert

Answer 1

Hi Beingolea Francisco,

Azure Key Vault pricing is per operation, not per certificate or per user request. In your scenario (Key Vault holding SSL certificates for web apps), the key vault will not be accessed on every user visit — it is only accessed when your app or Azure resource retrieves or updates a secret/certificate.

What actually counts as a Key Vault “operation”

Operations that are billed include:

GET / LIST of a secret, key, or certificate

SET / UPDATE / DELETE / IMPORT / RENEW of a secret, key, or certificate

Event Grid notifications (for alerts) – each event delivered counts as one event toward the Event Grid cost, not a Key Vault cost

Once an Azure service (like App Service) has fetched the certificate from Key Vault, it caches it locally. Users accessing your website do not trigger additional Key Vault calls.

Typical call volume in your scenario

Action	Approximate KeyVault operation	Frequency
Web App reads certificate	1 GET per certificate (on first load or when app restarts)	Few per month
Certificate renewal (from your container)	1 SET/IMPORT and 1 GET	Once per renewal
Once per renewal	1 event delivered (billed under Event Grid, not Key Vault)	Once per alert trigger

For 3 certificates, that’s usually fewer than a few dozen operations per month — only a few cents at Key Vault’s transaction rate.

How to estimate in the Azure Pricing Calculator

In the Azure Pricing Calculator:

• Add Key Vault → choose Standard or Premium tier.
• Under Operations, enter the estimated number of operations per month (e.g., 100–1,000).
  • Standard tier: ~$0.03 per 10,000 operations.
  • Premium tier (if using HSM keys): ~$0.15 per 10,000 operations.
• For alerts, add Event Grid separately (first 100,000 ops/month are free).