Factors that Affect Costs
Azure uses a consumption-based model — you pay only for what you use. Several factors drive the final bill:
| Factor | How it affects cost |
|---|---|
| Resource type | Each service has its own pricing dimensions (VM size, storage tier, database SKU) |
| Consumption | More usage = more cost. Reservations and savings plans offer discounts for predictable workloads |
| Maintenance | Orphaned resources (e.g., disks left after a VM is deleted) still accrue charges |
| Geography (Region) | Power, labor, and tax costs differ by region — the same resource may cost more in one region |
| Subscription type | Free trial includes credits and 12 months of popular free services; paid tiers differ in pricing |
| Azure Marketplace | Third-party solutions include both Azure infrastructure charges and the vendor's own licensing fee |
Network traffic (bandwidth) is also a cost factor. Azure uses billing zones — geographic groupings of regions — to price data egress. Inbound data is generally free; outbound data is billed by zone.
Pricing Options for Compute
The default model is Pay-as-you-goNo commitment; pay for actual usage each billing cycle. The default Azure pricing model — most flexible but highest per-unit cost. — most flexible but highest per-unit cost. For predictable, always-on workloads, Azure ReservationsCommit to a specific resource for 1 or 3 years in exchange for a significant discount (up to ~72% vs. pay-as-you-go). Best for predictable, always-on workloads. offer up to ~72% savings by committing to a specific resource for 1 or 3 years. For more flexibility across VM families and regions, the Azure Savings Plan for computeCommit to an hourly spend amount across eligible compute services for 1 or 3 years; Azure applies the best available price automatically. More flexible than reservations since it applies across VM families and regions. lets you commit to an hourly spend amount and Azure applies the best available price automatically. For interruptible batch workloads, Spot Virtual MachinesUse unused Azure capacity at steep discounts (up to 90%), but workloads can be evicted with 30 seconds notice when Azure needs capacity back. Best for fault-tolerant, interruptible workloads like batch jobs. use unused Azure capacity at up to 90% discount — but can be evicted with 30 seconds notice.
Pricing Calculator vs. TCO Calculator
Note: As of the current Microsoft Learn content, the TCO calculator has been retired. The Pricing Calculator is now the primary estimation tool.
| Tool | Purpose | Who uses it |
|---|---|---|
| Pricing calculator | Estimate the cost of Azure resources you plan to provision. Produces monthly/annual estimates for any combination of services. | Anyone planning a new Azure deployment |
| TCO calculator (retired) | Was used to compare on-premises infrastructure costs against an Azure migration scenario | Infrastructure architects evaluating migration business cases |
The Pricing calculator is for information purposes only — nothing is provisioned, and you are not charged for anything you configure in the tool.
Microsoft Cost Management
Microsoft Cost Management is a built-in Azure service with three key capabilities:
| Capability | Description |
|---|---|
| Cost analysis | Visualize and explore costs by subscription, resource group, service, region, or tag. Spot trends over billing cycles. |
| Cost alerts | Automatically notify stakeholders when spending reaches defined thresholds. Three alert types: budget alerts, credit alerts (EA only), and department spending quota alerts (EA only). |
| Budgets | Set spending limits by subscription, resource group, or service type. Budgets can trigger automation (e.g., shut down nonproduction resources) when thresholds are hit. |
Credit alerts fire at 90% and 100% of Azure credit balance for Enterprise Agreement customers.
Resource Tags
Resource tagsName-value pairs attached to Azure resources as metadata. They do not affect functionality but enable cost allocation, governance, automation, and operational classification of resources. are name-value pairs attached as metadata to resources — they have no effect on functionality but enable cost allocation, governance, and operational classification across your Azure estate:
| Use case | Example tag |
|---|---|
| Resource management | Owner: teamA |
| Cost management and optimization | CostCenter: CC-1234 |
| Operations management | Impact: Mission-critical |
| Security | DataClassification: Confidential |
| Governance and compliance | Regulation: ISO27001 |
| Workload optimization and automation | AppName: OrderService |
Important tag behaviors:
- Tags are not inherited — a tag on a resource group does not automatically appear on its child resources.
- Azure Policy can enforce required tags (deny resource creation if
CostCenteris missing) and can auto-add missing tags. - Tags can be managed from the Azure portal, PowerShell, Azure CLI, ARM templates, or the REST API.
Cost Factors — Impact Comparison
| Factor | Controllable by customer? | Cost reduction strategy |
|---|---|---|
| Resource type | Yes (choose service) | Use PaaS/Serverless instead of IaaS where possible |
| Consumption | Yes | Right-size VMs; use autoscaling; delete idle resources |
| Maintenance | Yes | Delete orphaned disks, IPs, NICs after VM deletion |
| Geography | Yes (choose region) | Deploy to lower-cost regions for non-latency-sensitive workloads |
| Subscription type | Limited | Use free tier for dev/test; EA for enterprise discounts |
| Marketplace | Yes (choose offering) | Evaluate BYOL vs. pay-as-you-go for third-party software |
Compute Pricing Options — Trade-off Matrix
| Option | Commitment | Discount | Eviction risk | Best for |
|---|---|---|---|---|
| Pay-as-you-go | None | None | None | Variable, unpredictable workloads |
| Reservations | 1 or 3 years | Up to ~72% | None | Stable, always-on workloads |
| Savings Plan | 1 or 3 years | Up to ~65% | None | Flexible compute, mixed VM types |
| Spot VMs | None | Up to ~90% | Yes (30-sec notice) | Batch, fault-tolerant, stateless |
Budget Alerts vs. Credit Alerts vs. Quota Alerts
| Alert type | Who it applies to | Trigger condition |
|---|---|---|
| Budget alert | All customers | Spending reaches % of user-defined budget |
| Credit alert | Enterprise Agreement (EA) customers | Azure credit balance reaches 90% or 100% |
| Department quota alert | EA customers with department quotas | Department spending reaches quota threshold |
Critical fact: A budget does NOT automatically block spending. It generates an alert and can optionally trigger an automation action (e.g., shut down VMs). You must configure the action group to stop resources.
Resource Tags — Governance and Cost Integration
Tags integrate with cost tools:
- Cost analysis — filter and group costs by tag (e.g., view all spending for
CostCenter: CC-1234). - Azure Policy — enforce tag presence; deny resource creation if required tags are missing.
- Chargeback/showback — allocate cloud costs to business units using tag-based filtering in Cost Management.
Explore Cost Tools in Azure
Step 1 — Use the Azure Pricing Calculator
- Navigate to azure.microsoft.com/pricing/calculator (no sign-in required).
- Search for Virtual Machines and add a D2s v5 instance.
- Change the Region from East US to West Europe — observe the price change (geography factor).
- Switch License to Azure Hybrid Benefit (if you have Windows Server licenses) — observe the discount.
- Change Payment option to 1 Year Reserved — compare the savings vs. pay-as-you-go.
Step 2 — Explore Cost Analysis
- Sign in to portal.azure.com.
- Search for Cost Management → open Cost Management + Billing.
- Navigate to Cost Management → Cost analysis.
- Use the Group by dropdown to slice costs by Service, Region, and Resource group.
- Change the chart to a daily view — spot any spending spikes.
Step 3 — Create a Budget Alert
- In Cost Management → click Budgets → + Add.
- Set a monthly budget amount (e.g., $50).
- Add an alert condition at 80% and enter your email in the action group.
- Click Create — you now have a cost predictability control.
Step 4 — Apply a Tag to a Resource
- Navigate to any resource (e.g., a storage account) in the portal.
- Click Tags in the left navigation under Settings.
- Add a tag: Name =
CostCenter, Value =CC-Demo. - Save — observe that sibling resources in the same resource group do NOT automatically inherit this tag.
AZ-900 Exam Focus
Exam Trap
"Use the TCO calculator to estimate the cost of new Azure resources" — Wrong. The TCO calculator was designed to compare on-premises vs. Azure migration costs (and has been retired). The Pricing Calculator is used to estimate the cost of new Azure resources.
Exam Trap
"Tags are inherited from resource groups to child resources" — Wrong. Tags are NOT inherited by default. You must apply tags explicitly at each level, or use Azure Policy to enforce inheritance-like behavior.
Exam Trap
"A budget in Cost Management automatically blocks spending when the limit is reached" — Wrong. A budget generates alerts and can optionally trigger automation actions; it does not block resource usage by itself unless you configure an action group to stop resources.
Exam Trap
"Spot VMs are guaranteed not to be interrupted if you pay more" — Wrong. Spot VMs can always be evicted when Azure needs capacity back, regardless of your spend level. They offer no SLA for availability.
Exam Tip
Pricing Calculator = pre-deployment estimation. Cost Management = live spending tracking. These tools are frequently swapped in wrong-answer distractors. Know which does which.
Must Memorize
Credit alerts = Enterprise Agreement only, fire at 90% and 100% of credit balance
Budget alerts = all customers, fire at user-defined % of user-defined budget
Tags = not inherited, not functional, managed by Policy for enforcement
Question — click to flip
Q: What is the difference between the Azure Pricing Calculator and Microsoft Cost Management?
Question — click to flip
Q: Are tags inherited from a resource group to its child resources?
Question — click to flip
Q: What does a Cost Management budget do when the spending threshold is reached?
Question — click to flip
Q: What are Spot Virtual Machines and what is their key risk?
Question — click to flip
Q: Which type of Cost Management alert is specific to Enterprise Agreement customers and fires at 90% of the Azure credit balance?
Question — click to flip
Q: Name three factors that affect Azure costs.