Cost factors and the Azure Pricing Calculator¶
Azure does not have one universal price. A solution's cost is the result of multiple meters, configuration choices, discounts, and usage patterns. AZ-900 questions usually ask which factor changes cost or which tool estimates cost before deployment.
The cost model¶
Estimated Azure cost
├── Service and SKU selected
├── Quantity and duration of use
├── Region
├── Data transfer
├── Software and support charges
└── Discounts and commitments
Factors that affect Azure cost¶
Resource type and service¶
Different services use different billing meters.
| Service | Example meters |
|---|---|
| Virtual Machines | VM size, operating system, runtime, disks, and network transfer |
| Blob Storage | Capacity, redundancy, access tier, operations, retrieval, and transfer |
| Azure Functions | Executions, execution duration, memory, and hosting plan |
| Azure SQL | Compute tier, provisioned/serverless model, storage, and backup retention |
Exam trap: creating a VM can also create separately billed supporting resources such as managed disks and a public IP address.
Service tier, SKU, and size¶
A larger VM, premium disk, or higher database tier normally costs more because it provides additional capacity, performance, or features.
- Scale up: increases the capacity and usually the price of one resource.
- Scale out: adds instances, increasing aggregate consumption.
- Scale in/down: can reduce cost when capacity is no longer needed.
Consumption and time¶
Pay-as-you-go charges follow the service's meter. Turning off an application does not necessarily stop every charge.
- A stopped but allocated VM can continue to incur compute charges.
- A deallocated VM stops compute billing, but disks and other retained resources can still cost money.
- Stored data continues to incur capacity charges even when it is not read.
Region¶
Prices can differ by Azure region because infrastructure, energy, taxes, demand, and service availability differ. Choose a region for compliance, latency, resilience, and cost—not cost alone.
Data transfer¶
The direction and destination of network traffic matter.
- Inbound data transfer to Azure is often free, with service-specific exceptions.
- Outbound transfer from Azure can be charged.
- Transfer between regions or availability zones can incur charges depending on the services and traffic path.
Exam rule: never assume all network transfer is free. Check the relevant service pricing page.
Software, marketplace, and support¶
Costs can include:
- Windows Server or SQL Server licensing;
- third-party Azure Marketplace software;
- support plans;
- managed-service or partner charges.
Ways to reduce cost¶
| Option | Best fit | Main trade-off |
|---|---|---|
| Pay-as-you-go | Uncertain or short-term usage | Highest flexibility, usually no commitment discount |
| Azure reservations | Predictable eligible resources for one or three years | Commitment reduces flexibility |
| Azure savings plan for compute | Predictable compute spend across eligible services | Hourly spend commitment |
| Azure Spot Virtual Machines | Interruptible, fault-tolerant workloads | Azure can evict the VM |
| Azure Hybrid Benefit | Existing eligible Windows Server or SQL Server licenses | Requires qualifying licenses |
| Right-sizing and autoscale | Match capacity to real demand | Requires monitoring and correct rules |
Reservations and savings plans are billing discounts; they do not automatically redesign, secure, or scale the workload.
Azure Pricing Calculator¶
The Azure Pricing Calculator estimates the expected cost of a proposed Azure solution before deployment.
Typical workflow:
- Add the Azure services the architecture needs.
- Select regions, tiers, sizes, quantities, and usage hours.
- Configure storage, transactions, data transfer, licensing, and support assumptions.
- Compare pay-as-you-go with eligible commitment discounts.
- Save, export, or share the estimate.
The result is an estimate, not a bill or guarantee. Actual cost can differ because usage, prices, exchange rates, taxes, discounts, and architecture change.
Tool comparison¶
| Question | Tool |
|---|---|
| What might this Azure design cost before deployment? | Azure Pricing Calculator |
| Which Azure resources are generating actual charges? | Cost Analysis in Microsoft Cost Management |
| How does current on-premises cost compare with a cloud migration? | Total Cost of Ownership (TCO) Calculator or migration assessment |
| Which changes could reduce cost in deployed resources? | Azure Advisor and Cost Management recommendations |
Scenario¶
A team is deciding between two VM sizes in West Europe and North Europe before creating anything.
Best fit: configure both options in the Azure Pricing Calculator and compare the assumptions.
Exam clues¶
- Estimate before deployment → Pricing Calculator.
- Actual historical or current cloud spend → Cost Management / Cost Analysis.
- Long-term predictable eligible workload → reservation or savings plan.
- Existing eligible Microsoft licenses → Azure Hybrid Benefit.
- Batch workload can tolerate eviction → Spot VM.
Check yourself¶
Statement: Deallocating a VM removes every cost associated with it.
Answer: False. Compute billing stops, but retained disks, snapshots, public IP configurations, or other supporting resources can continue to incur charges.