Uptime SLA Calculator

Enter your SLA target

Uptime Percentage (%)

Allowed downtime / day

Allowed downtime / week

Allowed downtime / month

Allowed downtime / year

Common SLA Levels

SLA Level	Common Name	Downtime / Month	Downtime / Year
99%	Two nines	7h 18m	3d 15h 36m
99.5%	Two and a half nines	3h 39m	1d 19h 48m
99.9%	Three nines	43m 50s	8h 45m 36s
99.95%	Three and a half nines	21m 55s	4h 22m 48s
99.99%	Four nines	4m 23s	52m 34s
99.999%	Five nines	26s	5m 15s

What is an SLA?

A Service Level Agreement (SLA) defines the guaranteed uptime for a service. It's expressed as a percentage of total time — for example, 99.9% uptime means your service can be down for no more than 43 minutes and 50 seconds per month. The more nines in your SLA, the less downtime is allowed.

How to choose the right SLA target

Your SLA target should match your business requirements and technical capabilities:

99% Suitable for internal tools, development environments, and non-critical services. Allows about 7 hours of downtime per month.
99.9% Standard for most SaaS products and business applications. Allows about 44 minutes of downtime per month. Achievable with basic redundancy.
99.99% Required for e-commerce, financial services, and critical infrastructure. Only 4 minutes of downtime per month. Requires multi-region deployment.
99.999% Mission-critical systems like payment processors and emergency services. Just 26 seconds per month. Requires sophisticated failover and redundancy across multiple providers.

Why monitoring matters for SLA compliance

You can't meet an SLA you don't measure. Monitoring from multiple global locations helps you detect outages within seconds, understand regional availability differences, and generate accurate uptime reports for SLA compliance. With Latency Global's 70+ probe locations, you can monitor your SLA from the same regions your users are in.

Frequently Asked Questions

SLA downtime = (1 - SLA percentage) x total time period. For example, 99.9% uptime over a 30-day month: (1 - 0.999) x 30 x 24 x 60 = 43.2 minutes of allowed downtime.

It depends on the SLA agreement. Many providers exclude pre-announced maintenance windows from SLA calculations. Always check the specific terms of your SLA.

Most SLAs include service credits — typically a percentage of your monthly bill proportional to the additional downtime. For example, if you had 99.9% SLA but actual uptime was 99.5%, you might receive 10-25% service credit.

Use an external monitoring service like Latency Global that checks your service from multiple locations worldwide. Internal monitoring alone can miss regional outages and network issues that affect real users.

Uptime measures whether a service is running. Availability is broader — it includes whether the service is accessible and performing within acceptable parameters. A slow-responding service may be "up" but not truly "available" to users.