AZ-900
Deep Dive
Tools for estimating, monitoring, and optimizing costs. Azure cloud can be cheaper than on-premises, but without active management it can surprise you with unexpected bills.
Contents
The Azure Pricing Calculator is a free web tool for estimating the monthly cost of an Azure architecture before implementing it. Ideal for budget planning and comparing configurations.
How it works
Select the Azure services you need (VM, SQL, Storage, etc.)
Configure the specifications: region, size, redundancy, hours of use
The calculator shows the estimated monthly cost per service and total
Export as PDF or share the estimate with your team
Example: simple web architecture
App Service (B2 · 1 instance · East US)
~$73/month
Azure SQL (S2 · 50 DTU · East US)
~$75/month
Azure Storage (100 GB LRS · Hot)
~$2/month
Application Insights (5 GB/month)
~$0 (free tier)
Azure CDN (100 GB transfer)
~$8/month
Estimated total
~$158/month
*Approximate estimate. Prices vary by region, tier, and usage commitments.
Pricing Calculator vs Azure Migrate business case — a distinction for the exam
Pricing Calculator
Estimates the cost of Azure services. Answers: "how much will this architecture cost me in Azure?"
Azure Migrate business case
Compares total on-premises cost vs Azure. Answers: "how much do I save by migrating to Azure?"
Use the Azure Pricing Calculator to build a monthly cost estimate for a simple web architecture.
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The Azure Migrate business case compares the total cost of ownership (TCO) of keeping your workloads on-premises with running them in Azure, based on the servers and databases that Azure Migrate discovers, and shows the estimated savings. It replaces the former TCO Calculator, which is no longer available. It includes hidden costs that many companies underestimate.
Hidden on-premises costs the business case accounts for
Hardware
Datacenters
IT Staff
Software
Operations
DR / BC
Real case: 200-employee company, migration to Azure
On-premises (real cost over 3 years)
Azure (estimated cost over 3 years)
Savings: $234,000 over 3 years (55%)
This is the kind of analysis the Azure Migrate business case produces to justify a migration to Azure
Cost Management + Billing is the Azure portal for monitoring, analyzing, and controlling active spend. Once you're using Azure, this is the day-to-day cloud finance tool.
Main capabilities
Cost Analysis
Breakdown of spend by service, resource, tag, region, subscription. Trend charts and forecasting.
Budgets
Define monthly budgets. Alerts when 50%, 80%, and 100% of the budget is reached. Can trigger automatic actions.
Recommendations
Savings suggestions: oversized VMs, recommended Reserved Instances, idle resources.
Exports
Export cost data to Azure Storage as CSV for analysis in Power BI, Excel, or your own tools.
Scenario: budget alert
Company with a $10,000/month Azure budget. Sets up three alerts:
Email to the finance manager with a breakdown
Email + Teams notification + Jira ticket to review
Email + SMS + automatically shut down dev VMs
Budgets are configured in Cost Management and use Action Groups (the same mechanism as Azure Monitor Alerts).
Reserved Instances (RI) / Reserved Capacity
Savings: 30–72%A 1- or 3-year usage commitment in exchange for a significant discount. You pay upfront (all at once or monthly) or with no upfront payment for a smaller discount.
When to use
Predictable workloads that run 24/7: production databases, stable web servers.
When NOT to use
Development environments, experimental workloads, workloads likely to change.
Numeric example
Standard_D4s_v3 VM in East US: Pay-as-you-go = $0.192/h ($140/month). 1-year RI = $0.119/h ($87/month). 3-year RI = $0.073/h ($53/month).
Azure Spot Instances
Savings: 60–90%Azure's spare compute capacity at massively discounted prices. Azure can reclaim the instance with 30 seconds' notice when it needs the capacity back.
When to use
Batch processing tolerant of interruptions, ML training, CI/CD workers, rendering.
When NOT to use
Never for critical production, databases, or workloads that can't be restarted.
Numeric example
Standard_D4s_v3 VM: Pay-as-you-go = $0.192/h. Spot = ~$0.042/h. 78% savings for a 48-hour ML job.
Right-sizing
Savings: 20–60%Adjust resource size to actual consumption. 40% of VMs in Azure are oversized according to Microsoft. Use Azure Advisor to identify them.
When to use
After 30+ days of usage data. Especially for resources created "just in case."
When NOT to use
Without prior usage data. Don't downsize without measuring the impact first.
Numeric example
Standard_D8s VM (8 vCPU, 32 GB RAM, $0.384/h) using 15% CPU and 4 GB RAM → downsize to Standard_D2s (2 vCPU, 8 GB RAM, $0.096/h). 75% savings.
Auto-shutdown and schedules
Savings: 40–70%Automatically shut down resources when not in use: dev VMs overnight and on weekends, QA environments only during business hours.
When to use
Development, testing, demo, and sandbox environments. Anything that doesn't need to run 24/7.
When NOT to use
Production, stateful databases, resources with long warm-up times.
Numeric example
Dev VM: 24/7 = $140/month. With auto-shutdown (8h active/day, M-F): 40h/week = 30% of the time = $42/month. Savings of $98/month.
Azure Advisor analyzes your configuration and usage, and generates personalized recommendations. It's free and accessible from the portal. It doesn't just recommend cost savings — it also suggests security, performance, and reliability improvements.
Cost
Oversized VMs, recommended Reserved Instances, unused resources you can delete, incorrect storage tiers.
Security
MFA not enabled, management ports exposed to the internet, resources without encryption, VM vulnerabilities.
Reliability (High availability)
VMs without Availability Sets/Zones, databases without backup, resources without sufficient SLA for their requirements.
Performance
Throttling detected on Storage, missing SQL indexes, CDN recommended for static content.
Operational excellence
Resources without diagnostics enabled, subscriptions without budget alerts, resources in deprecated regions.
| Factor | Impact | Example |
|---|---|---|
| Resource type | Large variation. Standard vs Premium VMs differ 2-5x. | Standard_B2s: $30/month. Standard_D8s_v3: $280/month. |
| Region | The same services can cost 10-30% more in expensive regions. | East US (cheaper) vs Brazil South (more expensive) ~25% difference. |
| Time of use | Most resources are billed by the hour or second. | VM running 24/7 vs only 8h/day = 3x cost difference. |
| Data transfer | Ingress is free. Egress (outbound to the internet) is billed per GB. | First 100 GB/month free. Then ~$0.087/GB in East US. |
| Tier / SKU | Basic vs Standard vs Premium with 3-10x differences. | SQL DB Basic: $5/month. SQL DB Business Critical Gen5: $1,000+/month. |
| Redundancy / SLA | More redundancy = higher cost. LRS is cheaper than ZRS, which is cheaper than GRS. | Storage LRS: $20/100GB. Storage GRS: $40/100GB (2x due to replication). |
| Licensing | Windows VMs cost more than Linux. SQL included in a VM costs more. | Linux Standard_D4 VM: $140/month. Same-size Windows VM: $260/month. |
Azure Hybrid Benefit — savings with existing licenses
If your company has Windows Server or SQL Server licenses with Software Assurance, you can use them in Azure at a discount. Azure Hybrid Benefit can reduce the cost of Windows VMs by up to 40% and SQL Server by up to 55%.
Configure a monthly budget in Cost Management to control your subscription's spend. Cost management is a domain of the AZ-900 exam (FinOps).
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Which Azure tool lets you analyze current spend, create budgets, and receive alerts when 80% of the budget is reached?
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