PromoHive Venture

Uptime Budget Calculator

% uptime allows 43.8 min of downtime a month

Common targets

Three nines is 99.9, four nines is 99.99

A 30-day month, drawn to scale: days down, hours across, one cell an hour
Services a request depends on

Use each provider’s published availability. Leave a row empty to skip it

Your chain of services

99.8401%1 h 10 min of downtime a month

This chain tops out at 99.8401%, so a 99.9% target is out of reach. It uses about 26.3 min more downtime a month than the target allows.

Per day1.4 min
Per week10.1 min
Per month43.8 min
Per year8 h 46 min

A contract says 99.9% uptime and everyone nods

Few people know that allows about 43 minutes of downtime a month

The real figure is lower when your app depends on a database, a payment gateway and an SMS provider, because their downtime adds up. Teams usually find this out during the first outage instead of when they sign.

Calendar maths you can check

A month is the average of 30.44 days and a year is 365.25 days, so the numbers line up with standard SLA tables.

One month, 30 whole daysThe last 0.44 of a day, 10.5 hours
One year, 365 whole daysAnd a quarter

The grid at the top draws 30 whole days to keep the cells even. The figures count the average month, which is 10.5 hours longer

365.25 days ÷ 1230.4375 days
30.4375 days × 1,440 min43,830 min
365.25 days × 1,440 min525,960 min
(1 − 99.9 ÷ 100) × 43,83043.8 min
(1 − 99.9 ÷ 100) × 525,9608 h 46 min

Founders signing an SLA

Check what a promised uptime really allows before it goes into a contract.

Engineers planning on-call

See how much downtime a month leaves once every dependency is counted.