How Much Does an AWS Migration Cost? A Realistic Budget Guide
"What will moving to AWS cost us?" The honest answer is "it depends" — and that answer helps nobody's budget planning. So this article puts numbers on it: what drives the cost, the typical project ranges, the hidden line items everyone forgets, and how the budget should be split across phases — using the framework we apply on our own projects.
The short answer: typical ranges
| Scenario | Typical scope | Project cost range | Duration |
|---|---|---|---|
| Small: a few servers + database | 5-10 VMs, one application stack, mostly lift-and-shift | €25,000–40,000 | 4-8 weeks |
| Medium: mixed workloads | 10-40 servers, 2-5 applications, partial replatforming (managed DB, containers) | €40,000–80,000 | 2-4 months |
| Large: data center exit | 40+ servers, dependency webs, compliance requirements, hybrid period | €80,000–150,000+ | 4-9 months |
These figures are the cost of the migration project; the post-migration monthly AWS bill is a separate line, and in a properly right-sized environment it usually lands below the old hardware + licenses + maintenance + staffing total.
The 5 factors that drive the price
- 1. Migration strategy (the 6Rs): Rehosting (lift-and-shift) is cheapest and fastest; replatforming (e.g. moving the database to RDS) sits in the middle; refactoring (microservices, serverless) costs the most but pays the largest long-term dividend. Real projects are a mix — 60% rehost, 30% replatform, 10% refactor is a typical split.
- 2. Databases: The real center of gravity. Moving from licensed commercial engines (Oracle, MSSQL) to open source or managed services brings big savings but demands schema and application work. Same-engine moves to RDS are comparatively quick.
- 3. Dependency density: If nobody can answer "what breaks if this app goes down?", discovery takes longer. On old, undocumented estates, discovery is a budget item that should not be squeezed.
- 4. Downtime tolerance: There is a serious cost gap between "we can shut down over a weekend" and "five minutes max" — the latter requires parallel environments, data replication, and dry runs.
- 5. Compliance and security: GDPR, ISO 27001 or sector rules shape the landing zone, encryption, and logging design from day one. Bolting them on later is always more expensive.
The hidden line items everyone forgets
- The parallel-running period: Old and new environments run side by side for 1-3 months — you pay two bills. Budget for it.
- Data transfer: Ingress is free, but sync tooling, line capacity, and elapsed time on large datasets are not.
- License conversions: Bring-your-own-license portability varies by product; sometimes you re-purchase.
- Team enablement: Whoever operates the environment afterwards needs AWS competence — budget training or external support.
- Post-migration optimization: The first build is never the most efficient build. A right-sizing and cost pass 1-2 months after cutover typically cuts the bill by a permanent 15-30%.
How the budget splits: 30/40/30
- 30% — Discovery and design: Inventory, dependency map, 6R decisions, landing zone (account structure, network, IAM, security baseline), migration order and rollback plans. Skimping here returns as surprises later.
- 40% — Migration waves: Workloads move in waves; each wave is a rehearse → cut over → verify cycle. The riskiest systems go second, not last — the first wave proves the process, then you tackle the hard part before momentum fades.
- 30% — Stabilization and optimization: Monitoring and alerting, performance tuning, right-sizing, a commitment plan (see our Savings Plans vs Reserved Instances guide), and handover.
For the step-by-step technical plan, our cloud migration roadmap provides a detailed template.
Time-and-materials or fixed price?
Hourly contracts have a structural problem on migrations: the customer carries all the uncertainty risk, and a longer project is not against the consultant's interest. That is why we sell migrations at a fixed price: scope crystallizes during discovery, the price is signed, and overrun risk stays with us. Budget predictability is the sentence your CFO will like most about this project.
Frequently asked questions
How much does an AWS migration cost?
Typical ranges: €25-40K for small estates (5-10 servers), €40-80K for medium (10-40 servers), €80-150K+ for data center exits. The drivers are strategy mix, database conversions, and downtime tolerance.
How long does it take?
4-8 weeks for small projects, 2-4 months for medium, 4-9 months for large estates. What stretches timelines most is not the technical work but undocumented dependencies surfacing during discovery.
What happens to the monthly bill after migration?
Properly right-sized, it usually lands below the old hardware + licenses + maintenance + staffing total. But "migrate first, optimize later" means the first months run heavy — which is why the optimization pass belongs in the budget.
Is zero-downtime migration possible?
For most workloads, yes: data replication + a parallel environment + controlled DNS cutover gets downtime to minutes. It costs more; the economical path is to establish real tolerance per system with the business and decide case by case.
Bottom line
AWS migration cost is not a mystery — it is a discovery question: once your inventory, databases, and downtime tolerance are clear, so is the number. What is genuinely expensive is an unplanned migration; a workload moved twice always costs more than one moved right.
Want a number for your environment? Our AWS Migration service quotes a fixed price after discovery — overrun risk stays with us. Prefer a lighter start? Contact us for a free AWS health scan of your current estate's migration readiness.