Question 1

How do reserved instances save money?

Accepted Answer

Reserved instances (RIs) offer 30-75% discount vs on-demand in exchange for a 1 or 3-year commitment. A 1-year no-upfront RI saves ~40%; a 3-year all-upfront saves ~60-70%. Break-even vs on-demand is typically 6-8 months. Best for stable, predictable workloads.

Question 2

What are cloud egress costs?

Accepted Answer

Egress is the cost of data leaving the cloud provider. AWS charges $0.09/GB for the first 10TB per month transferred out to the internet. Data transfer between regions also incurs fees. Egress can be a significant and often overlooked cost for data-intensive applications.

Question 3

How do I calculate cloud vs on-premises TCO?

Accepted Answer

On-premises TCO includes hardware purchase (amortised), rack space, power, cooling, networking, and staff. Cloud TCO is compute, storage, data transfer, and management tools. Cloud typically wins for variable workloads; on-premises can win for stable, high-utilisation workloads above a certain scale.

Question 4

Are these cloud computing tools free?

Accepted Answer

Yes - completely free, no sign-up required. Results export to CSV or PDF.

Free Cloud Computing Tools & Calculators

Cloud calculators that prevent bill shock

Cloud Computing Tools - FAQ