SLA Uptime & Downtime Calculator

Stop guessing what your SLA means. Translate uptime percentages into exact minutes and seconds of allowable downtime per month and year.

Target Uptime

Quick Select "Nines":

Maximum Allowable Downtime

Per Year
8 hrs, 46 mins

If your servers are down longer than this, you break your SLA.

Per Month
43.8 mins
Per Week
10.1 mins
Per Day
1.4 mins

The Quest for "Five Nines"

In software engineering and cloud architecture, availability is measured in "nines". When an enterprise SaaS company signs a Service Level Agreement (SLA) with a client, they are legally binding themselves to a specific uptime percentage. If they fail, they must pay financial penalties.

What do the Nines mean?

  • Two Nines (99%): 3.65 days of downtime per year. (Acceptable for internal, non-critical tools).
  • Three Nines (99.9%): 8.77 hours of downtime per year. (Standard for most consumer SaaS).
  • Four Nines (99.99%): 52.6 minutes of downtime per year. (Enterprise grade).
  • Five Nines (99.999%): 5.26 minutes of downtime per year. (Telecoms, banking, life-saving medical tech).

The Exponential Cost of Uptime

Moving from 99.9% to 99.99% might seem like a small jump, but it requires completely changing your software architecture. It usually means implementing multi-region failovers, active-active databases, and 24/7 on-call DevOps teams. The cost of achieving "Five Nines" is exponentially higher than "Three Nines".

Frequently Asked Questions

What is the SLA Uptime Calculator?

The SLA Uptime Calculator is a free online tool designed to help you translate percentage uptime (99.99%) into allowable minutes of downtime.

How much does the SLA Uptime Calculator cost?

Our SLA Uptime Calculator is 100% free to use. We do not require any signups, subscriptions, or credit cards.

Is my data safe when using this tool?

Yes. All calculations are performed locally in your web browser. We do not store or save your financial data or inputs on our servers.