Compare Azure SQL Database DTU and vCore purchasing models including Business Critical replicas and backup storage.
The DTU model sells one opaque blended unit, while the vCore model prices compute, storage and replicas separately, which is why Business Critical costs roughly 2.7× General Purpose — it is provisioning three extra replicas and local SSD storage. Backup storage is free up to 100% of the database size, so only the incremental point-in-time history is billed. The DTU-to-vCore migration is a common cost surprise, and Business Critical is frequently bought for a workload that only needed General Purpose with a zone-redundant configuration; confirm the current DTU and vCore rates for your region in the Azure pricing calculator before signing off a design.
Azure SQL Cost
vCore compute = vCores × rate × 730 × tier factor (Business Critical bundles 3 secondary replicas); DTU compute = DTUs × per-DTU price; backup billing starts above 100% of the database size.
vCore compute = vCores × rate × 730 × tier factor (Business Critical bundles 3 secondary replicas); DTU compute = DTUs × per-DTU price; backup billing starts above 100% of the database size. The DTU model sells one opaque blended unit, while the vCore model prices compute, storage and replicas separately, which is why Business Critical costs roughly 2.7× General Purpose — it is provisioning three extra replicas and local SSD storage. Backup storage is free up to 100% of the database size, so only the incremental point-in-time history is billed.
The DTU-to-vCore migration is a common cost surprise, and Business Critical is frequently bought for a workload that only needed General Purpose with a zone-redundant configuration; confirm the current DTU and vCore rates for your region in the Azure pricing calculator before signing off a design.
This calculator takes 11 inputs: Purchasing model, DTUs provisioned, Price per DTU, vCores provisioned, General Purpose vCore rate, vCore service tier, Billed hours per month, Database size, Data storage price per GB, Point-in-time retention, Backup storage price per GB. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.