99.999% Uptime Downtime Calculator & SLA Allowance (Five Nines)
A 99.999% uptime target ("Five Nines") allows just 26.3 seconds of downtime per month, or 5 minutes and 15 seconds across an entire year. Five Nines is the gold standard for carrier-grade telecommunications, emergency response dispatch, and financial core transaction processing.
99.999% Maximum Allowed Downtime by Time Window
Exact permissible service unavailability before breaching the 99.999% SLA target.
0.864s per 24 hours
6.048s per 7 days
26.298s per billing month
315.576s per 365.25 days
Calendar Month Length Variance for 99.999% SLA
Contractual downtime allowances vary based on the number of calendar days in the billing period.
| Month Duration | Total Time Available | Max Allowed Downtime | Downtime in Seconds |
|---|---|---|---|
| 28 Days (February Common) | 2,419,200 sec (672 hrs) | 24.19s | 24.192s |
| 30 Days (Apr, Jun, Sep, Nov) | 2,592,000 sec (720 hrs) | 25.92s | 25.92s |
| 31 Days (Jan, Mar, May, Jul, Aug, Oct, Dec) | 2,678,400 sec (744 hrs) | 26.78s | 26.784s |
| Standard Average Month (30.4375 Days) | 2,629,800 sec (730.5 hrs) | 26.3s | 26.298s |
Comparing 99.999% Against the Table of Nines
Understand how each additional "nine" reduces allowable downtime by an order of magnitude (10x).
| Availability Tier | SRE Classification | Daily Allowance | Weekly Allowance | Monthly Allowance | Yearly Allowance |
|---|---|---|---|---|---|
| 90.0% | 1 Nine | 2h 24m | 16h 48m | 3d 1h 48m | 36.5 Days |
| 95.0% | 1.5 Nines | 1h 12m | 8h 24m | 1d 12h 54m | 18.26 Days |
| 99.0% | 2 Nines | 14m 24s | 1h 40m | 7h 18m | 3.65 Days |
| 99.5% | 2.5 Nines | 7m 12s | 50m 24s | 3h 39m | 1.83 Days |
| 99.9% | 3 Nines | 1m 26s | 10m 5s | 43m 50s | 8h 46m |
| 99.95% | 3.5 Nines | 43.2s | 5m 2s | 21m 55s | 4h 23m |
| 99.99% | 4 Nines | 8.64s | 1m 0s | 4m 23s | 52m 36s |
| 99.995% | 4.5 Nines | 4.32s | 30.2s | 2m 11s | 26m 18s |
| 99.999%Current | 5 Nines | 0.86s | 6.05s | 26.3s | 5m 16s |
| 99.9999% | 6 Nines | 0.086s | 0.60s | 2.63s | 31.56s |
Recommended Architecture Stack
Carrier-Grade Distributed Fault-Tolerant System
To reliably sustain a 99.999% SLA without exceeding error budgets, production systems typically implement:
- Active-Active multi-cloud / multi-datacenter topology with zero single points of failure (SPOF)
- Hardware-level redundancy with BGP Anycast and synchronous Raft / Paxos consensus
- Automated chaos engineering with continuous simulated node and datacenter termination
- Sub-second automated health verification and automated traffic isolation
Standard SLA Contract Clause Template
Ready-to-use legal snippet for Master Service Agreements (MSA)
Calculate Custom Outage Durations & Realized Availability
Have you experienced an unexpected API incident? Input your exact downtime duration into our dual-mode calculator to instantly evaluate SLA compliance, credit tier liabilities, and error budget burn.
Frequently Asked Questions (99.999% Uptime)
Clear answers to common SRE, contractual, and technical SLA calculation questions.
Frequently Asked Questions
In a 365.25-day year, 99.999% uptime allows exactly 5 minutes, 15 seconds, and 580 milliseconds of downtime.
Telecommunications carriers (e.g. cellular core backbones), 911 / emergency dispatch systems, stock exchanges (NASDAQ, NYSE), air traffic control, and hospital life-support monitoring networks.
Automate Your SLA Compliance Tracking with Uptara
Eliminate manual downtime spreadsheets. Continuously probe your APIs from global edge regions, aggregate quorum consensus, and export 1-click audit ledgers.