How the SLA credit calculator works
What is a cloud SLA?
A Service Level Agreement (SLA) is the provider’s contractual uptime commitment for a specific service - for example, AWS commits EC2 to 99.99% monthly uptime at the region level. When measured uptime falls below the commitment, the SLA specifies a service credit: a percentage of that service’s monthly charges returned to you as billing credit. The SLA also specifies how to claim it, what evidence is required, and how long you have.
Step 1 - Measure the uptime
Uptime is time-based: minutes the service was available divided by total minutes in the month. Using the standard 30-day month (43,200 minutes):
uptime % = (43,200 − downtime minutes) ÷ 43,200 × 100
94 minutes down → (43,200 − 94) ÷ 43,200 × 100 = 99.782%If you already have a measured uptime percentage from your own monitoring, the calculator accepts that directly instead.
Step 2 - Find the SLA tier
Each provider publishes tiered credit tables. The measured uptime falls into exactly one tier. For EC2, 99.782% falls in the “below 99.99%, at or above 99.0%” tier, which pays a 10% credit. The full tables for every service we track are on the provider pages: AWS, Azure, and GCP.
Step 3 - Apply it to your spend
The credit applies to the affected service’s charges for that month - not your whole bill. A 10% tier on a service you spend $12,000/month on is a $1,200 credit.
Where the SLA data comes from
The tier tables are transcribed from the providers’ official SLA documents - the AWS per-service SLAs, Microsoft’s consolidated SLA for Online Services, and Google Cloud’s per-product SLAs - and stored in a maintained data file with a visible “last verified” date (2026-07-01). When a provider revises its SLA, the file is updated and the date bumped. Source links appear under every table and in the footer of every page.
What the calculator does not do
- It does not measure your downtime for you - you bring the incident duration or a measured uptime percentage from your monitoring.
- It does not model service-specific exclusions (maintenance windows, customer-caused downtime, preview features), which providers can invoke against a claim.
- It is an estimate for informational purposes, not financial or legal advice; the SLA terms in force during your incident govern the actual credit.
Ready to act on a number? The claim guide covers evidence, deadlines, and exactly what to write to each provider.