CloudCostCompareHow we calculate monthly cloud costs, step by step
If you are going to trust a number, you should know how it was made. This guide describes the rules behind the figures on CloudCostCompare. The short version is on the methodology page; this is the longer explanation.
Prices come from the vendors
Every price is read from the vendor’s own public price source and keeps the vendor’s SKU and the date it was read. We do not type prices by hand, and we do not use third-party price aggregators. Each service links to the vendor’s own price page so you can check any line. See how prices are collected and refreshed.
The baseline is on-demand list price
Prices are public on-demand list prices in US dollars. That leaves out enterprise agreements, private contracts, committed-use and reservation discounts, spot prices, free allowances and tax. The reasons, and what that means for your real bill, are in list prices versus negotiated discounts.
A month is 730 hours
For anything billed by the hour, a month is the hourly price multiplied by 730, which is a year of 8,760 hours divided by twelve. This avoids a different answer in a 28-day and a 31-day month. Usage-based items such as messages, gigabytes or queries are priced on the quantity you enter, per month.
Equivalent services only
Two services are put side by side only when they do the same job and bill in a comparable way. The map that records this lists each job (for example “managed PostgreSQL”), names the service on each cloud, and writes down the reason for any difference. We never compare a burstable server with a fixed-performance one, or a service billed per scan with one billed per hour.
Gaps are never zero
- If a cloud does not offer a service, the line says Not offered and gives the reason.
- If a service is offered but cannot be sized from public information, it says Can’t be sized, with the reason.
- If a price could not be refreshed, the last good value is kept and flagged. If a price was never fetched, it shows as unavailable.
An estimate with any gap is incomplete. It ranks below complete ones and is never called the cheapest. You can see this on the compare pages and in every results table.
Regions
Comparisons use region groups, which pair the closest equivalent region on each cloud. A group is chosen for you, and you can switch it. A “same place” comparison is only fair when the regions are matched.
What we leave out on purpose
Taxes, support plans, marketplace software, discounts you negotiate, and the cost of your own people. Some of these matter a great deal. We leave them out because they cannot be known from public information and would make the figures look more precise than they are.
Where the formula is
Every line in the estimator has a formula expander showing the quantity and the working. The same functions produce the estimator, the example pages and the live tables in guides, so they cannot disagree. Read how to read a cloud cost estimate for a walk through a results table.