SolarWinds VM to Cloud Calculator: Compare On‑Prem VMs vs. Cloud Costs

How to Use the SolarWinds VM to Cloud Calculator for Accurate TCO EstimatesAccurately estimating total cost of ownership (TCO) when migrating workloads from on-premises virtual machines (VMs) to the cloud is critical for budgeting, buy-in, and long-term planning. The SolarWinds VM to Cloud Calculator is designed to simplify that process by helping you compare current on-prem costs with projected cloud expenses, account for migration and ongoing operational costs, and model different scenarios so stakeholders can make informed decisions. This guide walks through using the calculator step-by-step, explains the key inputs and outputs, and offers practical tips to improve accuracy.

What the SolarWinds VM to Cloud Calculator does

The calculator aggregates cost components across both environments and forecasts TCO over a chosen time horizon (commonly 1–5 years). It typically includes:

• On-premises costs: server hardware, hypervisor licenses, storage, networking, power/cooling, rackspace, administration and support labor, backup and DR, and depreciation.
• Cloud costs: compute (VM instances), storage, data transfer, managed services, licensing (BYOL vs. included), support plans, and potential reserved/spot discounts.
• Migration costs: professional services, tooling, refactoring, testing, and cutover labor.
• Operational differences: monitoring, security, backup, and performance tuning in the cloud.

Before you start: gather accurate inputs

Accuracy depends on quality of inputs. Collect the following data for each workload or VM class:

• VM name or group and purpose (e.g., web tier, database)
• vCPU count, RAM, and allocated storage (GB)
• Average CPU and memory utilization (percent)
• IOPS or throughput needs if available
• Current hypervisor and licensing costs (per-socket, per-VM, or subscription)
• Storage type and costs (SAN/NAS, SSD vs. HDD)
• Backup/replication costs and RTO/RPO requirements
• Network bandwidth and egress volumes (monthly GB transferred)
• Support and administration labor hours and rate
• Power, cooling, and rackspace costs (if estimated per-VM)
• Expected growth rate and planned consolidation ratios
• Migration project costs (one-time professional services, tooling)

If you lack exact numbers, use conservative estimates and run sensitivity scenarios.

Step-by-step: using the calculator

1. Choose scope and timeframe

   • Decide whether to model a single VM, a group of similar VMs, or your entire estate.
   • Select the TCO horizon (1, 3, or 5 years is common).

2. Enter on-premises baseline

   • Input hardware, storage, and networking costs allocated to the VM(s). If your accounting records provide monthly or annual totals, convert them to a per-VM basis. Include depreciation schedules if relevant.

3. Add software licensing and support

   • Add hypervisor licensing, OS licensing, database licenses, and support contracts. Note whether licenses are perpetual (one-time with maintenance) or subscription-based.

4. Enter operational and facility costs

   • Include sysadmin labor (hours per month × rate), backup and DR costs, power and cooling (kWh or per-VM estimate), and rackspace costs.

5. Model cloud configuration and pricing

   • Choose equivalent cloud instance types (or combinations) to match CPU, RAM, and performance needs. For databases or specialized workloads, select managed services (e.g., managed DB instances) when appropriate.
   • Enter storage type and IOPS requirements.
   • Add expected monthly outbound data egress.
   • Choose support plan (basic vs. premium) and decide whether you’ll BYOL (bring-your-own-license) or use included licensing.

6. Include migration costs

   • Add one-time migration professional services, refactoring, testing, and expected downtime or cutover labor. If using a migration tool subscription, include that cost.

7. Apply discounts and rightsizing assumptions

   • If you’ll use reserved instances, savings plans, or committed use discounts, enter those percentages or reservation terms.
   • Model rightsizing assumptions: cloud instances often allow more granular sizing; estimate the percentage of CPU/RAM reduction you’ll achieve post-migration.

8. Review outputs and run scenarios

   • Examine annual and cumulative TCO for on-prem vs. cloud. Look at break-even points, yearly cost differences, and per-VM cost deltas.
   • Run sensitivity scenarios: different utilization, different discount levels, higher/lower migration costs, and various growth rates.

Key outputs to inspect

• Cumulative TCO over the chosen timeframe (on-prem vs. cloud) — the primary comparison.
• Annual recurring costs for both environments — helps identify ongoing budget impacts.
• One-time migration costs and how they affect break-even timing.
• Per-VM or per-application cost — useful for chargeback/showback or prioritizing migration waves.
• Break-even point — when cloud cumulative spend overtakes or becomes lower than on-prem spend.
• Sensitivity ranges — shows how robust your decision is to changes in utilization, pricing, or discounts.

Common pitfalls and how to avoid them

• Underestimating data egress: Cloud egress can be a significant recurring cost for data-heavy apps. Measure current outbound traffic and model realistic growth.
• Ignoring licensing complexity: Some enterprise licenses don’t permit cloud use or have different pricing; validate with vendors.
• Forgetting operational change costs: Cloud operations often require new tooling and skills — add training, platform engineering, and potential staff changes.
• Overlooking performance differences: A cloud instance with the same vCPU/RAM may not deliver identical I/O or networking performance. Validate with pilot migrations.
• Using sticker-price cloud rates: Always model reserved instances, committed discounts, and negotiated enterprise discounts where available.

Tips to improve accuracy

• Start with a pilot: migrate a representative workload, measure actual cloud costs and performance, then refine assumptions and rightsizing rules.
• Use monitoring data: export historical utilization from vCenter, Hyper-V, or monitoring tools to size cloud instances accurately.
• Break workloads into classes: group by CPU-bound, memory-bound, I/O-bound, and bursty workloads; model each class separately.
• Include organizational factors: compliance, latency, and data sovereignty may require specific cloud regions or architectures that affect cost.
• Re-run the calculator periodically: cloud pricing, reserved instance options, and organizational needs change — update models before each migration wave.

Example scenario (high-level)

• 10 VMs (web/app): 2 vCPU, 4 GB RAM, 100 GB storage each, low I/O, average 15% CPU utilization.
• 2 VMs (db): 8 vCPU, 32 GB RAM, 1 TB NVMe storage, high I/O.
• On-prem allocated monthly cost per web VM: $120 (hardware, storage, power, licensing share).
• On-prem allocated monthly cost per db VM: $900.
• Cloud equivalent after rightsizing and discounts: web VM \(35/month, db VM \)420/month.
• One-time migration costs (tools + services): $12,000.

Result: The calculator would sum yearly on-prem vs. cloud costs, add migration costs, and show a 24–30 month break-even for moving the whole set depending on discount assumptions.

Post-analysis: what to do with results

• Use the TCO report to prioritize migration waves (migrate workloads with fastest payback first).
• Present per-application cost drivers to stakeholders to explain trade-offs (e.g., move low-I/O web tiers first; keep high-IO DBs on-prem or consider dedicated cloud infrastructure).
• Combine with performance testing and proof-of-concept migrations before large-scale moves.
• Revisit operational processes: update runbooks, backup/DR plans, and monitoring to the cloud-native model.

Final checklist before committing to cloud migration

• Gather precise utilization and data transfer metrics.
• Validate licensing terms and BYOL feasibility.
• Pilot at least one representative workload.
• Secure committed discounts or reservation plans if the migration is long-term.
• Plan for operational change: training, new tools, and governance.

Using the SolarWinds VM to Cloud Calculator methodically—feeding it high-quality inputs, modeling realistic discounts and rightsizing, and validating with pilots—produces actionable TCO estimates that reduce migration risk and give stakeholders confidence.