Technology

SLA Downtime Calculator

Free SLA downtime calculator. Convert SLA percentage to allowed downtime, calculate SLA from actual downtime, and check compliance. Supports all nines (99.9%, 99.99%, 99.999%) with yearly, monthly, and daily breakdowns.

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Calculate SLA Uptime and Allowed Downtime

Service Level Agreements (SLAs) guarantee specific uptime percentages. This calculator converts SLA percentages to allowed downtime, calculates what SLA your actual uptime achieves, and checks if you're meeting your SLA commitments.

Understanding SLA Calculations

SLA uptime percentages determine how much downtime is acceptable. The famous "nines" terminology describes reliability: 99.9% (three nines) allows about 8.77 hours of downtime per year, while 99.999% (five nines) allows only 5.26 minutes per year.

SLA Formula

Downtime = (100% - SLA%) × Total Time Period

Why Calculate SLA Downtime?

Understand SLA Commitments

Know exactly how much downtime your SLA allows per year, month, or day.

Track Compliance

Check if your actual uptime meets your SLA commitments and avoid penalties.

Plan Maintenance Windows

Schedule maintenance within your allowed downtime budget.

Compare Service Tiers

Understand the real difference between 99.9% and 99.99% SLA tiers.

How to Use This Calculator

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Common Use Cases

Cloud Service Selection

Compare AWS (99.99%), Azure (99.95%), and Google Cloud SLAs in real downtime minutes.

Maintenance Planning

A 99.9% monthly SLA allows 43.8 minutes of planned downtime per month.

Incident Response

After an outage, check if you've breached your SLA and by how much.

Contract Negotiation

Understand what upgrading from 99.9% to 99.99% actually means in practice.

Frequently Asked Questions

99.9% (three nines) allows 8.77 hours of downtime per year. 99.99% (four nines) allows only 52.6 minutes per year—a 10x improvement. Each additional nine reduces allowed downtime by a factor of 10.