Cloud Cost Calculator

Cloud costs can increase even when overall business usage appears stable. Common causes include resources that remain running when they are no longer needed, oversized infrastructure, growing storage, snapshots and backups, increased logging, data transfer charges, changing cloud pricing and development or test environments that run continuously.

The first step is to identify which services and workloads are responsible for the increase rather than reducing resources indiscriminately. A cloud cost assessment can help separate genuine business growth from avoidable cloud expenditure.

Start by comparing cloud consumption with actual workload usage. In AWS and Azure, opportunities are often found in underused compute, idle resources, oversized virtual machines, unnecessary storage, development environments that run continuously, and agreements that no longer match demand.

Built-in cost-management tools are a good starting point, but the best decisions also consider performance requirements, peak demand and application behaviour. A cloud cost assessment can identify which opportunities are practical and worth implementing.

Some cloud costs are easy to see, while others accumulate gradually. Common examples include idle compute resources, unattached storage, old snapshots, unnecessary data transfer, excessive logging, forgotten development environments and services that continue running after a project has changed.

Costs can also arise from architectural decisions. An application may technically run well in the cloud while using cloud resources inefficiently. This is why effective optimisation may need to look beyond individual infrastructure resources and consider how applications and workloads behave.

Potential cloud savings vary significantly between organisations, so a fixed savings percentage can be misleading. The opportunity depends on the current level of optimisation, resource utilisation, purchasing arrangements, workload patterns, architecture and operational practices.

Some environments may have straightforward opportunities such as idle or oversized resources. Others may require application or architectural changes before substantial long-term savings are possible. The Gislen calculator provides an indicative estimate; a detailed assessment is needed to validate potential savings against the actual environment.

Often, yes. Cloud optimisation does not automatically mean migrating platforms or rebuilding applications. Savings may be available through right-sizing resources, removing unused services, scheduling non-production environments, improving storage management or reviewing purchasing commitments.

However, some costs are driven by how an application was designed. In those cases, infrastructure optimisation alone may have limited impact. Application modernisation can then be considered where the expected operational or financial benefits justify the change.

Yes, when optimisation takes workloads and business requirements into account. Cloud cost optimisation is about removing unnecessary consumption—not indiscriminately reducing capacity.

Rightsizing an underused resource may reduce costs with little operational impact. Reducing capacity in a business-critical workload without understanding demand can, however, create risk. Decisions should protect the required performance, reliability, security and resilience.

Native cloud cost-management tools and recommendations are valuable starting points. They can identify issues such as idle resources, utilisation patterns and potential purchasing opportunities.

But not every recommendation can or should be implemented automatically. A resource may appear oversized while supporting a critical peak workload, and some inefficiencies originate in application architecture, database design, integrations or operational processes rather than the cloud resource itself. Engineering and business context are therefore important when deciding which recommendations are practical.

Yes, in some environments. An application designed for older infrastructure or migrated to the cloud with minimal changes may not make efficient use of cloud services.

Modernisation can sometimes reduce infrastructure requirements, improve scalability, change how workloads run or remove dependencies that contribute to unnecessary expenditure. However, modernisation has its own cost and risk. It should be considered when the expected business, operational and financial benefits justify the investment, rather than being treated as an automatic response to a high cloud bill.

Cloud optimisation is not usually a one-time exercise. New workloads are introduced, applications change, teams create resources and usage patterns evolve.

Organisations can maintain control by establishing clear ownership of cloud expenditure, monitoring cost trends, using tagging and allocation consistently, setting budgets and alerts, reviewing idle resources and periodically reassessing infrastructure and purchasing commitments. The aim is to make cost visibility part of normal cloud management rather than waiting for an unexpectedly high bill.

A detailed assessment can be useful when cloud expenditure is significant, costs are increasing without a clear explanation, optimisation tools identify opportunities that teams are unsure how to implement, or management needs greater confidence in the potential business case for change.

Unlike an indicative calculator result, a detailed assessment can examine actual workloads, infrastructure, usage patterns, architecture and commercial arrangements. This helps distinguish quick cost improvements from changes that require deeper engineering or modernisation work.