A practical guide to cloud migration costs
A plain-language model for estimating migration spend and keeping the bill predictable after you cut over.
Cloud migration costs are easier to control when you treat them as a sequence of decisions, not a single invoice.
This guide walks through the cost drivers teams usually miss, how to estimate them before you move, and how to keep spend predictable after cutover.
What actually drives the bill
The first invoice after a move is rarely the surprise. The surprise is the combination of unused capacity, data transfer, and tools that were never turned off in the old environment.
- Compute that was sized for a peak week, then left running
- Storage that was copied “just in case” and never reviewed
- Cross-region traffic that was free on the old network and is metered now
- Observability and backup products added during the project and never right-sized
Build an estimate before you commit
Start with current usage, not list prices. Map each workload to a target size, then add transfer, storage, and operations as separate lines.
A simple three-line model
- Run: the monthly cost of the target compute and managed services.
- Move: one-time transfer, dual-running, and staff time.
- Operate: backups, monitoring, and the people who will own the new stack.
If you cannot explain those three numbers to a finance partner, the estimate is not ready.