Multi Region Availability
Free Multi Region Availability calculator with clear step-by-step results.
About Multi Region Availability
Two independent regions make simultaneous failure far less likely.
Formula
Formula
Active-active availability = 1 − (1−a)²
Worked example
With the default values below, Multi Region Availability returns Active-Active Availability of 99.9999%. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Single-region availability (%)accepts 0–100
- 99.9
- Failover RTO (hours/year)minimum 0
- 8.76
Results
- Active-Active Availability
- 99.9999%
- Downtime (hours/year)
- 0.009
- Downtime Reduction
- 99.90%
Step by step
- 1Values used
- 2Formula
- 3Active-Active Availability= 99.9999
- 4Downtime (hours/year)= 0.009
- 5Downtime Reduction= 99.90
Assumptions and limits
- The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How does this calculator work?
Two independent regions make simultaneous failure far less likely.
Why does this matter?
Assumes full independent failure modes.