Rehosting runs $200–$500 per server, replatforming $500–$1,500, and refactoring $20,000–$500,000+ per application. Enterprise cloud migrations for mid-size organizations typically land between $500,000 and $3 million, with 38% exceeding budget by 23%. Organizations that only lift-and-shift see 40% lower ROI than those that modernize, yet 52% default to rehosting. This guide gives you the specific dollar ranges, percentages, and timelines to build a realistic migration budget.
What You'll Learn
- Per-server and per-application cost ranges for all three primary migration strategies
- Where the migration budget actually goes — phase-by-phase percentage allocations
- The hidden costs that blindside enterprise budgets (Oracle licensing, dual-running, egress fees)
- ROI timelines and payback periods for rehost, replatform, and refactor
- A head-to-head comparison across 12 decision dimensions
- The blended portfolio strategy that top-performing enterprises use
Per-Server and Per-Application Costs Vary 10× Across Strategies
A documented case study illustrates the tradeoff clearly: a monolithic order system on 20 VMs cost $60,000 to rehost versus $280,000 to refactor — but the refactored version cut monthly operational costs from $18,000 to $9,000, breaking even at 22 months. AWS reports Windows workload modernization can reduce operating costs by up to 70% through license elimination alone.
Total Migration Costs by Enterprise Size
| Enterprise Size | Server Count | Total Migration Cost | Typical Timeline |
|---|---|---|---|
| Small | 50–200 | $100,000–$500,000 | 2–6 months |
| Mid-size | 200–1,000 | $500,000–$3,000,000 | 6–18 months |
| Large | 1,000+ | $1,000,000–$10,000,000+ | 12–36 months |
The 6 R's: Vastly Different Cost Profiles
Lowest cost, fastest execution. AWS reports 31% average infrastructure savings, but independent research shows rehosted workloads can deliver negative 5–10% savings due to overprovisioned VMs. Carries 100% of existing technical debt. ~50–60% of enterprise portfolios.
Productive middle ground. Targeted changes — e.g. self-managed PostgreSQL → Amazon RDS — eliminate licensing and operational overhead without full redesign. Achieves 26% average savings within 14–18 months at 1.5–3× the rehost cost. ~20–25% of portfolios.
Highest upfront at 3–5× rehosting, but cloud-native workloads achieve 35–45% lower TCO long-term. Netflix's full re-architecture to AWS microservices is the canonical example. Only 10–15% of workloads merit this treatment but consume 34% of total migration spend.
Replaces on-premises software with SaaS. Implementation costs cover consultants, training, and change management. Oracle reports cloud migration returns $3.86 for every $1 spent. Common moves: on-prem CRM → Salesforce; on-prem ERP → cloud SAP S/4HANA.
The only strategy that generates pure savings. Eliminates licensing, maintenance, hardware, and support costs. Auditing typically reveals 10–25% of the IT portfolio as retirement candidates — making this the highest-ROI activity in any migration program.
Avoids migration costs but sustains CapEx for hardware refreshes every 3–5 years. Hybrid networking adds $1,000–$10,000+/month for AWS Direct Connect or Azure ExpressRoute. Fits latency-sensitive, regulated, or end-of-life applications.
Where the Migration Budget Actually Goes
The Hidden Costs That Blindside Enterprise Budgets
This is where most migration budgets blow up — and none of it shows up in the vendor's proposal.
For a $500K–$3M total migration: budget approximately $100,000–$300,000 for assessment and planning, $200,000–$1,000,000 for migration labor, $50,000–$200,000 for data transfer and parallel-run costs, and $100,000–$500,000 for post-migration optimization.
ROI Timelines: Refactoring Pays Back Most, but Slowest
For sustained GPU/AI workloads, Lenovo's analysis shows on-prem infrastructure costs roughly $872,000 over 5 years vs. $4.3 million for equivalent AWS capacity — making on-prem 3–5× cheaper for continuous use. The break-even for continuous GPU workloads is ~12 months. This explains why 21% of cloud workloads have been repatriated, with cost cited as the primary reason by 54% of organizations.
2025–2026 Market Data: Spending Surging, Waste Persisting
Only 10% of cloud transformations achieve their full value per McKinsey — but companies that build a solid cloud foundation first see 8× acceleration in migration pace and 50% reduction in migration costs. Flexera 2025 found 27% of IaaS/PaaS spend is wasted industry-wide — roughly $195 billion annually.
Rehost vs. Replatform vs. Refactor: The Head-to-Head Verdict
| Dimension | Rehost | Replatform | Refactor |
|---|---|---|---|
| Upfront cost per app | $5,000–$100,000 | $20,000–$250,000 | $20,000–$500,000+ |
| Cost multiplier | 1× (baseline) | 1.5–3× | 3–5×+ |
| Migration speed | Days to weeks per workload | Weeks to months | Months to quarters |
| Break-even | 6–12 months | 12–18 months | 18–36 months |
| 3-year savings vs. on-prem | 10–20% | 20–35% | 30–50% |
| 5-year savings | Plateaus; debt compounds | 25–40% | 40–65% cumulative |
| Technical risk | Low | Moderate | High |
| Cloud-native benefits | Minimal | Partial | Maximum |
| Developer productivity | None | Slight | ~25% improvement |
| Technical debt | 100% carried forward | Partially addressed | Eliminated |
| Skill requirement | General IT/infra | Cloud + DevOps | Advanced cloud-native |
| Typical portfolio share | 50–60% | 20–25% | 10–15% |
Rehost 50–60% of workloads to establish cloud operations quickly. Replatform 20–30% where managed services offer clear licensing or operational savings. Refactor only the 10–15% of applications most critical to competitive differentiation. The most expensive mistake isn't choosing the wrong strategy for one app — it's treating rehosting as the final destination.
Key Takeaways
1. The 10× cost spread is real. Refactoring costs 3–5× more upfront but yields 30–50% lower ongoing costs and eliminates technical debt that otherwise compounds annually.
2. Budget overruns are the norm. With 38% of projects overrunning by 23% on average, a 20–25% contingency buffer isn't conservative — it's realistic.
3. Hidden costs dwarf infrastructure costs. Oracle licensing surprises, 6–12 month dual-running periods, and $5,000–$15,000 per-engineer training collectively represent a larger budget risk than cloud compute pricing.
4. FinOps is not optional. Organizations without formal cloud financial management waste 32–40% of cloud spend. Budget for it from day one.
5. The blended portfolio strategy outperforms. Rehost the commodity, replatform the database-heavy, refactor only what directly drives revenue. Enterprises using this approach consistently outperform on both migration speed and long-term ROI.
Get a Migration Cost Estimate for Your Portfolio
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