Quick answer: Cloud migration cost estimation forecasts two things: the one-time cost of the migration project and the ongoing monthly cost of running workloads in the cloud. Accurate estimates use real utilization data to right-size resources, include licensing, storage, networking, backup and support, apply pricing commitments for steady workloads, and compare the result with the full cost of staying on-premises.
Key takeaways
- Separate one-time migration costs from ongoing run costs, and estimate both.
- Size cloud resources from measured utilization, not from current hardware specifications.
- Licensing, storage, backup and data egress are commonly underestimated.
- Compare against the full on-premises total cost of ownership, including refresh cycles and staff time.
- Reserved capacity, savings plans and nonprofit programs can substantially change the result.
Cost is usually the first question in any cloud migration conversation and the most common source of disappointment afterward. Estimates that look attractive on paper can miss licensing, storage or networking costs, and migrated servers are often far larger than they need to be. This guide explains how to build an estimate you can rely on. It is part of our cloud migration services guidance.
What makes up the cost of a cloud migration?
Cloud migration cost has two components: one-time project costs to plan and execute the move, and ongoing run costs for operating workloads in the cloud. Both need estimating, and they trade off against each other.
| Category | Includes |
|---|---|
| One-time project costs | Assessment, planning, landing zone setup, migration labor, application changes, testing, training, parallel running, decommissioning |
| Ongoing run costs | Compute, storage, databases, networking, backup, licensing, monitoring, security tools, support plans, operations staff or managed service |
Strategy choice moves money between the two. Rehosting minimizes project cost but can carry a higher run cost; replatforming and refactoring spend more up front to reduce run cost. See the 7 Rs of cloud migration.
What drives one-time migration cost?
One-time cost is driven by the number of workloads, their complexity and the chosen strategy. Simple rehosts of standard servers are the cheapest; applications that need code or architecture changes cost the most.
Key drivers:
- Number of servers, applications and databases
- Strategy per workload, from retire through refactor
- Data volume and quality, including cleansing needs
- Dependencies and integrations that require testing
- Compliance requirements adding controls and documentation
- Parallel running of old and new environments during waves
- Training for staff who will operate the cloud environment
What drives ongoing cloud cost?
Ongoing cost is driven primarily by how resources are sized and how they are priced. The same workload can cost very different amounts depending on these choices.
| Driver | Effect on cost | How to manage it |
|---|---|---|
| Right-sizing | Oversized VMs are the most common waste | Size from measured utilization, review after migration |
| Running hours | Non-production resources often run 24/7 needlessly | Schedule shutdowns outside working hours |
| Pricing model | On-demand is the most expensive for steady workloads | Use reserved capacity or savings plans for baseline usage |
| Managed services | Can replace VMs plus admin effort | Replatform databases and web apps where practical |
| Storage tier | Premium storage is costly for cold data | Use tiering and lifecycle policies |
| Licensing | Windows Server, SQL Server and third-party licenses add significantly | Use eligible license benefits; consider open-source alternatives |
| Data egress | Data leaving the cloud is charged | Design to keep traffic in-region and in-cloud |
| Logging and monitoring | Log ingestion grows quietly | Set retention and filter noisy sources |
How do you build a reliable estimate?
Build a reliable estimate from measured data, apply realistic pricing assumptions, and include every cost category. The process below works across Azure, AWS and Google Cloud.
- Collect utilization data with discovery tools during a cloud readiness assessment, covering peak periods.
- Assign a strategy to each workload.
- Right-size each workload to measured peaks plus reasonable headroom.
- Price it using the provider's pricing calculator in your chosen region.
- Add supporting services: backup, monitoring, networking, security tooling and support plans.
- Apply licensing rules and eligible license benefits.
- Model pricing commitments for stable workloads, such as one- or three-year reservations or savings plans.
- Estimate project costs with ranges per wave.
- Compare against the on-premises total cost of ownership.
How do you calculate on-premises total cost of ownership?
On-premises total cost of ownership (TCO) includes far more than server purchase prices. A fair comparison spreads hardware over its useful life and includes every supporting cost.
On-premises TCO checklist:
- Server, storage and network hardware, amortized over the refresh cycle
- Hardware maintenance and warranty extensions
- Operating system, database and virtualization licenses
- Backup hardware, software and offsite storage
- Power, cooling and physical space
- Internet and site connectivity
- Staff or contractor time for patching, monitoring and troubleshooting
- Disaster recovery capability, or the business risk of lacking it
- Security tools and incident response readiness
The broader trade-offs are covered in our cloud vs on-premises comparison.
How do licensing and nonprofit programs affect cost?
Licensing and nonprofit programs can change the estimate more than any sizing decision. They should be examined early, not after the platform is chosen.
- Microsoft license benefits. Azure Hybrid Benefit can let organizations with eligible Windows Server and SQL Server licenses apply them in Azure, which can significantly lower costs for Microsoft-heavy workloads.
- Bring-your-own-license rules differ between providers and software vendors, so check terms before assuming portability.
- Nonprofit programs. Microsoft, AWS and Google each run nonprofit programs that may include credits, grants or discounts, and TechSoup helps eligible organizations validate status. Terms change, so confirm current eligibility directly.
- Startup and migration credits are sometimes available through provider programs or partners for qualifying migrations.
Which tools help estimate cloud cost?
Every major provider offers free estimation tools. They are most accurate when fed measured utilization data rather than hardware specifications.
| Provider | Estimation tools |
|---|---|
| Microsoft Azure | Azure pricing calculator, TCO calculator, Azure Migrate cost assessments |
| Amazon Web Services | AWS Pricing Calculator, Migration Evaluator |
| Google Cloud | Google Cloud Pricing Calculator, Migration Center cost estimates |
How do you keep actual costs close to the estimate?
Keep costs on track by setting budgets and alerts before migration, tagging every resource, and reviewing spend monthly in the first quarter. Most overruns come from forgotten resources and oversized machines, both of which are easy to catch early.
Platform-specific guidance is available in the Azure cost optimization guide, the AWS cost optimization guide and GCP cost optimization. After cutover, post-migration optimization turns the estimate into an ongoing discipline.
How Desai InfoTech estimates migration costs
Desai InfoTech builds estimates from measured utilization, includes licensing and supporting services, and presents both project and run costs as ranges alongside an on-premises TCO comparison. Request a free cloud assessment to get an estimate grounded in your own data.
Frequently asked questions
How much does it cost to migrate to the cloud?
Costs vary widely with the number of workloads, data volume, complexity and strategy. A small file-share and server migration is typically a few weeks of effort, while multi-application migrations with replatforming take months. Ongoing cloud cost depends on right-sizing, licensing and pricing commitments. A readiness assessment using real utilization data is the reliable way to get a ranged estimate for your environment.
Is the cloud cheaper than on-premises for a small business?
It depends on the workloads and how well the environment is managed. The cloud removes hardware purchases, refresh cycles, server-room costs and much maintenance work, while adding monthly consumption charges. Organizations that right-size, use managed services, shut down idle resources and commit to reserved pricing for steady workloads often come out ahead. A like-for-like TCO comparison is the honest test.
What hidden costs should we watch for in a cloud migration?
Commonly missed costs include software licenses that do not transfer to the cloud, data egress charges when data leaves the cloud, backup and long-term retention storage, premium storage tiers, public IP addresses, VPN or private connectivity, monitoring and logging ingestion, and running source and target environments in parallel during migration. Staff time for training and process changes should also be budgeted.
Which tools can estimate cloud costs?
Each provider offers free tools. Azure has the Azure pricing calculator, the TCO calculator and Azure Migrate cost estimates. AWS offers the AWS Pricing Calculator and Migration Evaluator. Google Cloud offers its pricing calculator and Migration Center cost estimates. These tools are most accurate when fed with measured utilization data from discovery rather than hardware specifications.
Part of the Cloud Migration Services hub.